Technical Field
[0001] The present invention relates to an improvement of a brittle sheet-like object such
as a laminate obtained by integrally laminating a glass sheet on a resin sheet, and
to an improvement of a cutting technology and a processing technology therefor.
Background Art
[0002] Laminates obtained by integrally laminating a glass sheet on at least one of both
surfaces of a resin sheet (glass sheet laminates) have various characteristics such
as high hardness, high durability, high airtightness, gas barrier property, and luxury
appearance, which are derived from the glass, and also have various characteristics
such as lightweight property and high impact resistance, which are derived from the
resin. Thus, the laminates of this type are expected for use in a wide variety of
fields, for example, as materials for panels of electric and electronic devices as
typified by flat panel displays (FPDs) such as liquid crystal displays and plasma
displays, portable electronic devices such as mobile phones and tablet PCs, solar
cells, and induction cookers, or as materials for window panels of building structures
and various vehicles. In particular, as described in Patent Literatures 1 and 2, a
laminate obtained by integrally laminating a relatively thinner glass sheet on a relatively
thicker resin sheet may contribute to lightweighting of various panels as compared
to a case of using a glass sheet having the same thickness as the laminate. Thus,
the laminate is expected for use in applications that promote lightweighting of products,
such as
[0003] FPDs and portable electronic devices.
Citation List
Summary of Invention
Technical Problems
<First Technical Object>
[0005] By the way, in a case where the glass sheet of the laminate is thinned to, for example,
a thickness of 300 µm or less, if an edge portion of an end surface of the glass sheet
is angulated, there is a risk in that the glass sheet may be damaged when another
member such as conveyance means strikes against the glass sheet.
[0006] Even if the glass sheet is not damaged, there may arise another problem in that the
resin sheet and the glass sheet are separated from each other when another member
strikes against the glass sheet. Such separation is mainly caused by stress concentration
that occurs in the end surface of the glass sheet when another member strikes against
the glass sheet. Further, when the glass sheet is separated from the resin sheet,
the glass sheet may be damaged later on due to the separation, and there arises a
new problem in that the shape of the appearance is deteriorated, resulting in reduction
in commercial value of the product.
[0007] In Patent Literature 1, however, the edge portion of the end surface of the glass
sheet integrally laminated on the resin sheet is angulated and sharpened, and hence
no consideration is taken for the damage to the glass sheet and the separation that
occurs between the glass sheet and the resin sheet (see FIGS. 1 of Patent Literature
1 and FIG. 1 of Patent Literature 2).
[0008] Further, apart from the shape of the end surface of the glass sheet, in Patent Literatures
1 and 2, the end surface of the glass sheet and the end surface of the resin sheet
are located on the same plane, thus increasing a probability that another member is
brought into direct contact with the end surface of the glass sheet. Therefore, the
above-mentioned problems of the damage to the glass sheet and the separation of the
glass sheet are liable to arise.
[0009] Still further, in general, expansion and contraction of the resin sheet due to a
temperature change are extremely significant relative to the glass sheet. Therefore,
if the end surface of the resin sheet and the end surface of the glass sheet are aligned
on the same plane, when the resin sheet contracts due to the temperature change, there
may occur, depending on the manner of adhesion, such a situation that the end surface
of the glass sheet protrudes with respect to the end surface of the resin sheet. In
this case, the probability of contact between the end surface of the glass sheet and
another member increases significantly, and hence the problems of the damage to the
glass sheet and the separation of the glass sheet become more conspicuous.
[0010] The present invention has been made in view of the above-mentioned circumstances,
and it is therefore a first technical object thereof to reduce damage to a glass sheet
and separation of the glass sheet in a laminate obtained by integrally laminating
the glass sheet on a resin sheet.
<Second Technical Object>
[0011] By the way, the above-mentioned laminate is generally used by being cut into a shape
and dimensions in accordance with the intended application.
[0012] When the laminate is ground through use of a diamond tool or the like for processing
glass, however, resin chips resulting from the grinding adhere to a grinding surface
of the tool so as to clog the tool. Thus, the grinding performance is decreased earlier.
As a result, the processing rate is decreased significantly, and further, excessive
runout occurs in the tool, thus leading to a risk of damage to the tool and the laminate.
[0013] When the laminate is ground through use of a cutting blade for processing a resin,
on the other hand, the cutting blade applies an excessive impact to the glass sheet,
thus leading to the risk of damage to the glass sheet.
[0014] In view of the above, the inventors of the present invention conducted extensive
studies focusing on laser fusing as a method of cutting a laminate. As a result, the
inventors of the present invention found the following new problems.
[0015] That is, when the amount of heat of the laser fusing is insufficient, only the resin
sheet is cut, and thus the glass sheet cannot be cut. When the amount of heat of the
laser fusing is excessively large, on the other hand, the entire laminate can be cut,
but the resin sheet is ignited and a large crack is generated in a cut surface of
the glass sheet.
[0016] The present invention has been made in view of the above-mentioned circumstances,
and it is therefore a second technical object thereof to set an appropriate amount
of heat of laser fusing, thereby accurately cutting a laminate obtained by integrally
laminating a glass sheet on a resin sheet.
<Third Technical Object>
[0017] Further, as the cutting method for a laminate, water jet cutting and the like are
employed instead of the laser fusing, but when the above-mentioned laminate is cut
by those cutting methods, the cut surface of the glass sheet is formed into an uneven
surface (rough surface) having a small defect such as breaking and chipping. Further,
the cut surface of the resin sheet is also formed into an uneven surface (rough surface)
due to, for example, melting caused by a thermal effect at the time of laser irradiation,
or due to roughening caused by abrasive grains at the time of water jet cutting. As
long as the cut surface having such surface property is left standing, there is an
extremely high risk of a critical problem with the quality of a product having the
laminate built therein, such as breaking of the glass sheet that is generated at a
point starting from the small defect. Therefore, it can be said that a process of
finishing the cut surface of the laminate (glass sheet and resin sheet) is preferably
executed after the above-mentioned laminate is cut into a predetermined shape and
dimensions.
[0018] In this case, when the end edge portions of the glass sheet and the resin sheet are
ground at the same time, it is considered that the processing efficiency of finishing
can be enhanced. However, the inventors of the present invention found that those
methods were liable to cause the following problems.
[0019] When the glass sheet and the resin sheet are ground at the same time with a grinding
tool such as a diamond tool, a part of the grinding surface of the grinding tool (portion
for grinding an object to be processed), which is brought into contact with the resin
sheet, is liable to be clogged earlier for such a reason that the resin is a highly
viscous material. When the grinding is continued under a state in which the clogging
occurs, the resin sheet cannot be shaved off in a predetermined manner, and hence
large fibrous resin chips are liable to be generated due to thermal deformation of
the resin sheet that is caused by friction between the resin sheet and the grinding
tool. The large resin chips are not easily discharged to the outside of the processing
point, and hence the glass sheet is compressed by the generated resin chips. As a
result, the damage to the glass sheet and the like are liable to occur.
[0020] In order to avoid the above-mentioned problems to the extent possible, it is considered
that measures of decreasing the grinding efficiency (decreasing the feed speed of
the grinding tool), increasing the maintenance or replacement frequency of the grinding
tool, and the like only need to be taken. Even when any of those measures are taken,
however, the processing efficiency is decreased significantly.
[0021] The present invention has been made in view of the above-mentioned circumstances,
and it is therefore a third technical object thereof to provide a processing technology
capable of efficiently finishing, with a predetermined accuracy, a cut surface of
a laminate obtained by integrally laminating a glass sheet on a resin sheet.
<Fourth Technical Object>
[0022] Further, when the inventors of the present invention carried out laser fusing on
a laminate obtained by integrally laminating glass sheets on both surfaces of a resin
sheet to divide the laminate into a product portion and a non-product portion, a small
defect such as a microcrack was in some cases formed in the cut end surface of the
glass sheet that formed the product portion. Such trouble occurred similarly when
the laser fusing was carried out on a glass sheet alone or a laminate obtained by
integrally laminating a glass sheet on only one surface of a resin sheet. In particular,
when the laser fusing was carried out on a glass sheet that was thinned to a thickness
of about several hundreds of micrometers or less (or a laminate including the glass
sheet), the frequency of formation of the small defect was increased more significantly.
Therefore, the inventors of the present invention conducted extensive studies and
found as a result that the small defect was liable to be formed in the cut end surface
of the product portion in a case where the manner of supporting the brittle sheet-like
object during the execution of the laser fusing was not appropriate, in particular,
in a case where, in the brittle sheet-like object, the non-product portion (or a region
to be formed into the non-product portion) was located even slightly higher than the
product portion (or a region to be formed into the product portion). An overview of
the inventors' findings is described with reference to FIGS. 39a and 39b.
[0023] FIG. 39a schematically illustrates a state immediately before a laminate 100 obtained
by integrally laminating glass sheets 102 on both surfaces of a resin sheet 101 is
divided into a product portion 100a and a non-product portion 100b through the laser
fusing. The laminate 100 is supported in a horizontal posture by a support member
110 arranged on a bottom side thereof. The support member 110 includes a first support
section 111 capable of supporting (in contact) the product portion 100a (or a region
to be formed into the product portion 100a), and a second support section 112 capable
of supporting (in contact) the non-product portion 100b (or a region to be formed
into the non-product portion 100b). A part or all of a support surface of the second
support section 112 is located slightly higher than a support surface of the first
support section 111, and hence the support member 110 has a region in which a small
gap is formed between a lower surface of the product portion 100a and the support
surface of the first support section 111. Further, when the small gap is formed particularly
in a region including a completion point of the laser fusing, immediately before the
laser fusing is completed (see FIG. 39b), the product portion 100a of the laminate
100 drops due to a self-weight thereof or the like by an amount corresponding to a
gap width of the above-mentioned small gap, with the result that the lower glass sheet
102 is forcibly snapped. Thus, a small defect 120 such as a microcrack is formed in
the lower glass sheet 102 that forms the product portion 100a, and in the worst case,
the lower glass sheet 102 that forms the product portion 100a is broken due to the
small defect 120.
[0024] The above-mentioned problems may arise similarly in a case where a glass sheet alone
that is the brittle sheet-like object is divided into the product portion and the
non-product portion through so-called laser cleaving.
[0025] The present invention has been made in view of the above-mentioned circumstances,
and it is therefore a fourth technical object thereof to optimize a manner of supporting
a brittle sheet-like object when dividing the brittle sheet-like object into a product
portion and a non-product portion through laser irradiation along a preset cutting
line, thereby reducing, to the extent possible, a risk in that a small defect is formed
in an end surface or the like of the product portion along with the division of the
brittle sheet-like object into the product portion and the non-product portion.
Solution to Problems
<First Invention>
[0026] According to a first invention devised to achieve the above-mentioned first technical
object, there is provided a laminate, comprising: a resin sheet; and a glass sheet
having a thickness of 300 µm or less, the glass sheet being integrally laminated on
at least one of both surfaces of the resin sheet, wherein an end surface of the glass
sheet is chamfered. Note that, the resin sheet and the glass sheet herein encompass
those having a thin film-like shape (hereinafter referred to simply as "films") (the
same applies hereinafter).
[0027] According to this structure, the end surface of the glass sheet of the laminate is
chamfered, and hence an angular portion is cut off from the end surface of the glass
sheet. As a result, even when another member strikes against the end surface of the
glass sheet, stress concentration occurring in the end surface of the glass sheet
is relieved, and thus the damage to the end surface of the glass sheet and the separation
that may occur between the glass sheet and the resin sheet can be prevented to the
extent possible.
[0028] In the above-mentioned structure, it is preferred that at least a part of an end
surface of the resin sheet protrude with respect to the end surface of the glass sheet.
[0029] With this structure, even if there occurs such a situation that another member is
brought into contact with the end surface of the laminate, the another member is preferentially
brought into contact with the end surface of the resin sheet that protrudes with respect
to the end surface of the glass sheet, and hence the another member is not easily
brought into direct contact with the end surface of the glass sheet. As a result,
the damage to the end surface of the glass sheet and the separation that may occur
between the glass sheet and the resin sheet can be prevented more reliably.
[0030] In the above-mentioned structure, it is preferred that the glass sheet be integrally
laminated on each of both the surfaces of the resin sheet.
[0031] With this structure, each outermost layer of the laminate is formed of glass, and
hence the durability or the like of the laminate can be enhanced reliably. Further,
in a case where the glass sheet is integrally laminated on only one surface of the
resin sheet, a warp of the laminate caused by a change in ambient temperature may
become conspicuous due to a difference in thermal expansion between the resin sheet
and the glass sheet. Therefore, also from the viewpoint of preventing such a warp,
it is preferred that the glass sheet be integrally laminated on each of both the surfaces
of the resin sheet.
[0032] In the above-mentioned structure, it is preferred that a corner portion formed by
crossing adjacent two edges have a curved shape or a polygonal shape obtained by combining
obtuse angles. Note that, the curved shape means that the corner portion is smoothly
and continuously formed into a substantially arc-like shape.
[0033] According to this structure, the corner portion of the laminate does not have an
acute angle portion of 90° or less. Therefore, even when the ambient temperature of
the laminate is changed abruptly, the stress concentration occurring in the corner
portion is relieved, and hence the glass sheet and the resin sheet are not easily
separated from each other.
[0034] In the above-mentioned structure, it is preferred that a deformed portion formed
of a projecting portion or a depressed portion be formed on an outer periphery of
the laminate, and when the deformed portion comprises a bending portion, the bending
portion have a curved shape. Note that, the curved shape means that the bending portion
is smoothly and continuously formed into a substantially arc-like shape.
[0035] According to this structure, the bending portion formed in the projecting portion
or the depressed portion on the outer periphery of the laminate does not have an acute
angle. Therefore, even when the ambient temperature of the laminate is changed abruptly,
the stress concentration acting on the bending portion is relieved, and the glass
sheet is not easily damaged.
[0036] In the above-mentioned structure, it is preferred that an opening portion be formed
in a flat surface of the laminate, the opening portion comprise a bending portion
on a periphery thereof, and the bending portion have a curved shape. Note that, the
curved shape means that the bending portion is smoothly and continuously formed into
a substantially arc-like shape.
[0037] According to this structure, the bending portion formed in the opening portion of
the laminate does not have an acute angle. Therefore, even when the ambient temperature
of the laminate is changed abruptly, the stress concentration acting on the bending
portion is relieved, and the glass sheet is not easily damaged.
[0038] According to the first invention devised to achieve the above-mentioned first technical
object, there is provided a manufacturing method for a laminate, comprising: a lamination
step of integrally laminating a glass sheet having a thickness of 300 µm or less on
at least one of both surfaces of a resin sheet; and a chamfering step of chamfering
an end surface of the glass sheet that is integrally laminated on the resin sheet
in the lamination step.
[0039] That is, in a case of chamfering an end surface of a glass sheet having a thickness
of 300 µm or less, the glass sheet alone is liable to be damaged, and it is extremely
difficult to chamfer the end surface thereof with a grinding wheel or the like. In
contrast, according to the above-mentioned method, the end surface of the glass sheet
is chamfered after the glass sheet is integrally laminated on the resin sheet. Thus,
as compared to the case of the glass sheet alone, the effect of reinforcing the glass
sheet with the resin sheet is expected, and hence the end surface of the glass sheet
can be chamfered easily.
[0040] In the above-mentioned structure, the chamfering step may comprise chamfering the
resin sheet as well.
[0041] With this structure, it can be expected that the strength against the damage is further
enhanced in the entire laminate.
[0042] In the above-mentioned structure, the lamination step may comprise integrally laminating
the glass sheet on each of both the surfaces of the resin sheet.
<Second Invention>
[0043] According to a second invention devised to achieve the above-mentioned first technical
object, there is provided a laminate, comprising: a resin sheet; and glass sheets
having a thickness of 300 µm or less, the glass sheets being integrally laminated
on both surfaces of the resin sheet, wherein at least a part of an end surface of
the resin sheet protrudes with respect to end surfaces of the glass sheets.
[0044] According to this structure, at least the part of the end surface of the resin sheet
actively protrudes with respect to the end surfaces of the glass sheets, and hence,
for example, even in a case where another member is laterally brought into contact
with the laminate, the another member is preferentially brought into contact with
the end surface of the resin sheet relative to the end surfaces of the glass sheets.
Therefore, it is possible to reduce such a situation that another member is brought
into direct contact with the end surfaces of the glass sheets. Further, even if thermal
contraction occurs in the resin sheet, at least the part of the end surface of the
resin sheet protrudes in advance, and hence it is also possible to avoid such a situation
that the end surfaces of the glass sheets protrude with respect to the end surface
of the resin sheet. Thus, it is possible to reliably reduce such a situation that
the glass sheet is damaged or separated at a point starting from the end surface thereof
due to the contact between the laminate and the another member.
[0045] In the above-mentioned structure, each of the end surfaces of the glass sheets may
comprise a tapered surface inclined away from the end surface of the resin sheet toward
an outer surface side of each of the glass sheets.
[0046] With this structure, the end surfaces of the glass sheets are gradually spaced away
from the end surface of the resin sheet toward the outer surface side of the glass
sheets, and hence it is possible to more reliably reduce the probability that another
member is brought into contact with the end surfaces of the glass sheets.
[0047] In the above-mentioned structure, the resin sheet and the glass sheets may be adhered
to each other with adhesive layers.
[0048] With this structure, the glass sheets can be fixed to the resin sheet easily and
reliably.
[0049] In the above-mentioned structure, end surfaces of the adhesive layers may protrude
with respect to the end surfaces of the glass sheets.
[0050] With this structure, the adhesive layers are larger in size than the glass sheets,
and hence the adhesive layers reliably act on the entire surfaces of the glass sheets,
thus leading to a preferred manner also from the viewpoint of preventing the separation
of the glass sheets.
[0051] In the above-mentioned structure, the end surfaces of the glass sheets and the end
surface of the resin sheet may be formed continuous with each other into a projecting
curved surface.
[0052] With this structure, at least the part of the end surface of the resin sheet can
easily protrude with respect to the end surfaces of the glass sheets while also chamfering
the end surfaces of the glass sheets.
<Third Invention>
[0053] According to a third invention devised to achieve the above-mentioned second technical
object, there is provided a cutting method for a laminate, comprising carrying out
laser fusing by irradiating the laminate with a laser beam from one side thereof,
the laminate being obtained by integrally laminating glass sheets on both surfaces
of a resin sheet, the laser beam having a focal point adjusted inside the laminate
at a position that is set within a range of more than 50% and 90% or less of an overall
thickness of the laminate from an incident surface side of the laser beam.
[0054] The inventors of the present invention conducted extensive studies and found as a
result that the position of the focal point of the laser beam was important to set
an appropriate amount of heat when carrying out the laser fusing on the laminate.
That is, it seems that the laminate can be cut efficiently when the position of the
focal point of the laser beam is set to a center of the laminate in a thickness direction
thereof, but in this case, there arose a problem in that the glass sheet located opposite
to the incident side of the laser beam (the glass sheet located on the incident side
of the laser beam is hereinafter referred to also as "incident-side glass sheet",
and the glass sheet located opposite to the incident side of the laser beam is hereinafter
referred to also as "non-incident-side glass sheet") was not cut. The reason is considered
that molten foreign matter generated at the time of cutting inhibits the propagation
of the laser beam and the heat is not easily transferred to the non-incident-side
glass sheet. The molten foreign matter herein refers to foreign matter such as dross,
which is generated along with fusing of the glass sheets and the resin sheet, and
encompasses both foreign matter in a molten state and foreign matter in a solid state.
[0055] Note that, it is considered that the power of the laser beam be increased under a
state in which the position of the focal point of the laser beam is set to the center,
but in this case, an excessive amount of heat is applied to the incident-side glass
sheet and a part of the resin sheet in the vicinity of the incident-side glass sheet,
which may cause such a situation that a crack is generated in the cut surface of the
incident-side glass sheet or the resin sheet is ignited.
[0056] Therefore, in the present invention, as in the above-mentioned structure, the position
of the focal point of the laser beam is set within the range of more than 50% and
90% or less of the overall thickness of the laminate from the incident surface side
of the laser beam. Thus, the position of the focal point of the laser beam is located
closer to the non-incident-side glass sheet, and hence a sufficient amount of heat
is also transferred toward the non-incident-side glass sheet, with the result that
the non-incident-side glass sheet can also be cut accurately. In this case, the reason
why the upper limit value, that is, 90% or less of the overall thickness is provided
to the position of the focal point of the laser beam is that, when the value exceeds
the upper limit value, conversely, the heat of the laser beam is not easily transferred
toward the incident-side glass sheet, which may cause cutting failure.
[0057] In the above-mentioned structure, it is preferred that the position of the focal
point be set within a range of 60% or more and 80% or less of the overall thickness
of the laminate from the incident surface side of the laser beam.
[0058] With this structure, the heat of the laser beam can be transferred more efficiently
to all of the three sheets, that is, the incident-side glass sheet, the resin sheet,
and the non-incident-side glass sheet.
[0059] In the above-mentioned structure, a value obtained by dividing power of the laser
beam by scanning speed of the laser beam may be set to 0.001 to 1 W·min/mm. In this
case, in a case where the laser beam used in the laser fusing is, for example, a pulsed
laser, an expression of "laser power=peak power×(pulse width/pulse period)" is established.
Further, the scanning speed of the laser beam refers to relative speed between the
laminate and the laser beam.
[0060] With this structure, the amount of heat of the laser beam to be applied to the irradiation
point of the laser beam is optimized, and hence the cutting of the laminate can be
achieved more accurately.
[0061] In the above-mentioned structure, it is preferred that the resin sheet have a thickness
of 20 mm or less, the glass sheets have a thickness of 300 µm or less, and the resin
sheet be thicker than the glass sheets.
<Fourth Invention>
[0062] According to a fourth invention devised to achieve the above-mentioned third technical
object, there is provided a processing method for a laminate, comprising: a cutting
step of cutting the laminate obtained by integrally laminating a glass sheet on at
least one of both surfaces of a resin sheet; and a finishing step of finishing a cut
surface of the laminate that is formed in the cutting step, the finishing step comprising:
a first phase of processing a cut surface of the glass sheet by grinding, and leaving
at least a part of a cut surface of the resin sheet in an unprocessed state; and a
second phase of processing only the cut surface of the resin sheet that is left in
the unprocessed state. Note that, the operation of "finishing a cut surface of the
laminate" herein refers to an operation of, for example, cutting off the end portion
including the cut surface by predetermined dimensions, to thereby finish the cut surface
of the laminate into a smooth surface having no small defect or the like (or finish
the cut surface of the laminate into a surface to the extent that, even if the small
defect is formed, the small defect causes no problem with the quality).
[0063] As described above, when finishing the cut surface of the laminate, the first phase
is first executed to process (finish) the cut surface of the glass sheet by grinding,
and to leave at least the part of the cut surface of the resin sheet in the unprocessed
state. With this method, when grinding the cut surface of the glass sheet (end portion
including the cut surface), large resin chips are not easily generated, and in addition,
the resin sheet functions as a backup member for the glass sheet so that the glass
sheet is not easily distorted when a grinding tool is pressed against the cut surface
of the glass sheet. From the facts described above, when executing the grinding in
the first phase, trouble such as breaking and chipping of the glass sheet can be prevented
to the extent possible while increasing the feed speed of the grinding tool so as
to enhance the finishing efficiency of the glass sheet. Further, in the second phase
subsequent to the first phase of the finishing step, only the cut surface of the resin
sheet that is left in the unprocessed state is processed (finished). Thus, a processing
method suited to finish the resin can be selected for use, and hence the cut surface
of the resin sheet can be finished efficiently. As described above, in the present
invention, the finishing of the cut surface of the laminate, which may be completed
even in a single phase, is executed in two separate phases intendedly. Therefore,
it seems that the man-hours and cost required to finish the cut surface are increased,
but the amount of processing efficiency enhanced by employing the present invention
is larger than the amount of processing efficiency decreased due to the above-mentioned
problems that may arise in the case of employing the conventional methods. Thus, according
to the present invention, the cut surface of the laminate obtained by integrally laminating
the glass sheet on the resin sheet can be finished efficiently.
[0064] Note that, in the grinding to be executed in the first phase, from the viewpoint
of preventing the clogging of the grinding tool and therefore preventing the breaking
of the glass sheet due to the clogging to the extent possible, it is desired to process
only the cut surface of the glass sheet. However, it is not easy to grind only the
cut surface of the glass sheet without grinding any part of the cut surface of the
resin sheet, and when such grinding is to be achieved, it is necessary to manage and
control grinding conditions with extreme precision, thus leading to a risk of increase
in processing cost on the contrary. Therefore, in the first phase in which the grinding
is executed, at least the part of the cut surface of the resin sheet is left in the
unprocessed state. Conversely, a part of the cut surface of the resin sheet is allowed
to be ground in the first phase. Thus, the grinding conditions in the first phase
can be relaxed, and the grinding can be executed rapidly. Note that, it is important
that the grinding range for the cut surface of the resin sheet be limited to a range
in which large resin chips are not generated even when the resin sheet is ground,
in other words, a range in which the grinding tool is not clogged (is not easily clogged).
[0065] In the above mentioned structure, it is desired that the grinding in the first phase
is executed (progressed) under a state in which a grinding tool is brought into contact
with a surface to be processed (cut surface of the glass sheet, or the cut surface
of the glass sheet and a part of the cut surface of the resin sheet) at a constant
contact force.
[0066] With this structure, an excessive pressure is not easily applied to the glass sheet
during the grinding, and hence the glass sheet is not easily broken. Therefore, the
feed speed of the grinding tool can be increased so as to enhance the processing efficiency
of the first phase in the finishing step.
[0067] In the above-mentioned structure, the grinding in the first phase may be executed
a plurality of times through use of grinding tools having different surface roughnesses
(grit sizes) of grinding surfaces thereof.
[0068] With this structure, the cut surface of the glass sheet is easily finished in a more
rapid manner as compared to the case of executing the first phase through use of a
single grinding tool. When taking a specific example, first, the surface to be processed
is roughly ground through use of a first grinding tool having a relatively larger
surface roughness of the grinding surface (having a relatively smaller grit size),
and then the surface to be processed is precisely ground through use of a second grinding
tool having a relatively smaller surface roughness of the grinding surface (having
a relatively larger grit size). In this case, the surface to be processed can be precisely
finished in the phase of grinding through use of the second grinding tool while securing
a necessary and sufficient grinding amount by the grinding through use of the first
grinding tool. Thus, the surface to be processed can be finished efficiently. As a
matter of course, the grinding in the first phase may be executed through use of three
or more types of grinding tool.
[0069] In the above-mentioned structure, the second phase may comprise processing, by cutting
work, only the cut surface of the resin sheet that is left in the unprocessed state.
[0070] The cutting work is executed through use of a working tool such as a so-called end
mill, in which the distance between adjacent blade portions is large so that the working
tool is not easily clogged. Thus, the feed speed of the working tool can be increased
so as to finish the cut surface of the resin sheet efficiently. In particular, of
the cutting tools, a so-called non-coated cutting tool having no protective coating
formed on a surface thereof has blade portions (cutting edges) exposed in a sharp
state without being covered with the protective coating, and hence the sharpness for
cutting a resin is more satisfactory as compared to a so-called coated cutting tool.
Thus, when the cut surface of the resin sheet is processed through use of the non-coated
cutting tool, the cut surface of the resin sheet may be finished particularly efficiently.
[0071] The processing method according to the present invention described above is particularly
suited to finish the cut surface of the laminate in which the glass sheet alone has
a thickness of 0.01 mm or more and 0.7 mm or less. This is because the breaking, chipping,
and the like are liable to occur particularly in the thin glass sheet described above.
[0072] Further, the processing method according to the present invention described above
is also suited to finish the cut surface of the laminate in which the thickness of
the glass sheet alone is smaller than a thickness of the resin sheet. This is because
the problems inherent in the above-mentioned conventional methods are more conspicuous
when finishing a cut surface of a laminate obtained by integrally laminating a relatively
thinner glass sheet on a relatively thicker resin sheet.
<Fifth Invention>
[0073] According to a fifth invention devised to achieve the above-mentioned fourth technical
object, there is provided a cutting apparatus for a brittle sheet-like object, which
is configured to cut a preset cutting line of the brittle sheet-like object, which
is supported in a horizontal posture from a bottom side thereof by a support member,
by radiating a laser beam along the preset cutting line so as to divide the brittle
sheet-like object into a product portion and a non-product portion across the preset
cutting line, the support member comprising: a first support section capable of supporting
the product portion; and a second support section capable of supporting the non-product
portion, wherein a support surface of the first support section is located higher
than a support surface of the second support section.
[0074] As described above, of the first and second support sections provided in the support
member, the support surface of the first support section is located higher than the
support surface of the second support section. Thus, the work of radiating the laser
beam, that is, the work of cutting the preset cutting line can be progressed and completed
under a state in which the product portion (or the region to be formed into the product
portion) is located constantly higher than the non-product portion (or the region
to be formed into the non-product portion). Therefore, it is possible to reduce, to
the extent possible, the risk in that a small defect such as a microcrack is formed
in the cut end surface of the product portion (end surface formed along with the division
of the brittle sheet-like object into the product portion and the non-product portion
across the preset cutting line through the cutting of the preset cutting line; the
same applies hereinafter) in the phase immediately before the completion of the cutting
of the preset cutting line due to the fact that the product portion is located lower
than the non-product portion.
[0075] Note that, when the support surfaces of both the support sections are provided at
the same height, as compared to the case where the support surface of the first support
section is located lower than the support surface of the second support section, the
risk of formation of the small defect in the cut end surface of the product portion
may be reduced to the extent possible. However, a processing error at the time of
manufacturing the support member is not easily eliminated in a complete manner, and
when a support member in which the support surfaces of both the support sections are
provided at the same height is to be obtained while eliminating the processing error
in a complete manner, considerable man-hours and cost are required to manufacture
the support member. Further, the respective sections of the support member are thermally
deformed due to the irradiation heat of the laser beam or the like, with the result
that a small height difference may also be generated between the support surfaces
of both the support sections during the execution of the cutting process. Still further,
when the heights of the support surfaces of both the support sections are set equal
to each other, it is not determined whether the above-mentioned small defect is generated
in the cut end surface of the product portion or the cut end surface of the non-product
portion. In contrast, according to the above-mentioned structure of the present invention,
the above-mentioned small defect is reliably generated in the cut end surface of the
non-product portion, and hence those problems can be solved to the extent possible,
which is advantageous in terms of the manufacturing cost of the support member and
the quality of the product.
[0076] In the above-mentioned structure, the support surface of the first support section
may be located higher than the support surface of the second support section within
a range of 0.01 mm or more and 0.2 mm or less.
[0077] When the cutting of the preset cutting line is completed under the state in which
the product portion is located higher than the non-product portion, as described above,
it is possible to reduce, to the extent possible, the risk in that the small defect
is formed in the cut end surface of the product portion. However, when the height
difference between both the support surfaces is extremely small, it is hard to deny
a risk in that a part or all of the support surface of the first support section is
located lower than the support surface of the second support section due to effects
of the processing error at the time of manufacturing the support member and/or thermal
deformation of the support sections along with the irradiation with the laser beam.
Therefore, when the support surface of the first support section is located higher
by 0.01 mm or more than the support surface of the second support section, the height
difference can absorb the amount of the processing error at the time of manufacturing
the support member and the amount of the thermal deformation of the support sections
along with the irradiation with the laser beam. In a case where the support surface
of the first support section is located higher by more than 0.2 mm than the support
surface of the second support section, on the other hand, the amount of hanging down
the non-product portion due to a self-weight thereof becomes larger, and due to a
bending stress generated therefrom, there is a risk in that the small defect is formed
in the product portion (and further, the product portion is broken). As described
above, it is desired that the support surface of the first support section be located
higher than the support surface of the second support section within the range of
0.01 mm or more and 0.2 mm or less.
[0078] In the above-mentioned structure, the cutting apparatus further comprise an elevating
mechanism for raising and lowering at least one of the first support section and the
second support section.
[0079] With this structure, during the execution of the cutting process for the preset cutting
line, the heights of the support surfaces of both the support sections can be adjusted,
and hence the cutting of the preset cutting line is easily progressed and completed
under a state in which the respective portions of the brittle sheet-like object are
held in an optimum posture.
[0080] The above-mentioned cutting apparatus may be used suitably when the brittle sheet-like
object is a laminate obtained by integrally laminating a glass sheet on at least one
of both surfaces of a resin sheet. In particular, the cutting apparatus may be used
suitably when a laminate obtained by using the glass sheets each having a thickness
of 0.01 mm or more and 1.0 mm or less, and the resin sheet having a thickness of 0.01
mm or more and 10 mm or less is to be divided into the product portion and the non-product
portion.
[0081] Further, the above-mentioned cutting apparatus may also be used suitably when the
brittle sheet-like object is a glass sheet. In particular, the cutting apparatus may
be used suitably when the glass sheet having a thickness of 0.01 mm or more and 1.0
mm or less is to be divided into the product portion and the non-product portion.
[0082] According to the fifth invention devised to achieve the above-mentioned fourth technical
object, there is provided a cutting method for a brittle sheet-like object, comprising
cutting a preset cutting line of the brittle sheet-like object, which is supported
in a horizontal posture from a bottom side thereof by a support member, by radiating
a laser beam along the preset cutting line so as to divide the brittle sheet-like
object into a product portion and a non-product portion across the preset cutting
line, the cutting of the preset cutting line being completed under a state in which
the product portion is located higher than the non-product portion, the state being
achieved at least immediately before completion of the cutting of the preset cutting
line.
[0083] According to this structure, it is possible to obtain the same actions and effects
as those in the case of employing the above-mentioned cutting apparatus for a brittle
sheet-like object.
[0084] In the above-mentioned structure, the product portion and the non-product portion
may be located at the same height during a period after start of the cutting of the
preset cutting line until immediately before the completion of the cutting of the
preset cutting line.
[0085] With this structure, the cutting of the preset cutting line can be progressed under
a state in which the product portion and the non-product portion are located within
the same plane. Thus, it is possible to reduce, to the extent possible, the probability
of formation of the small defect caused by the product portion or the non-product
portion that is hung down due to the self-weight thereof.
[0086] The above-mentioned structure may be employed particularly suitably when cutting
the preset cutting line by melting and removing the preset cutting line due to irradiation
heat of the laser beam, that is, when dividing the brittle sheet-like object into
the product portion and the non-product portion by so-called laser fusing.
Advantageous Effects of Invention
[0087] As described above, according to the first invention and the second invention, it
is possible to reduce, to the extent possible, such a situation that the end surface
of the glass sheet is damaged and the glass sheet and the resin sheet are separated
from each other.
[0088] Further, according to the third invention, it is possible to set an appropriate amount
of heat of the laser fusing by optimizing the position of the focal point of the laser
beam inside the laminate, thereby accurately cutting the laminate.
[0089] Further, according to the fourth invention, it is possible to efficiently finish,
with a predetermined accuracy, the cut surface of the laminate obtained by integrally
laminating the glass sheet on the resin sheet.
[0090] Further, according to the fifth invention, it is possible to optimize the manner
of supporting the brittle sheet-like object when dividing the brittle sheet-like object
into the product portion and the non-product portion through the laser irradiation
along the preset cutting line, thereby reducing, to the extent possible, the risk
in that the small defect is formed in the cut end surface of the product portion along
with the division of the brittle sheet-like object into the product portion and the
non-product portion.
Brief Description of Drawings
[0091]
FIG. 1 is a sectional view illustrating a laminate according to a first embodiment
of the present invention.
FIG. 2 is an enlarged view illustrating the region X in FIG. 1.
FIG. 3 is an enlarged sectional view illustrating a main part of a laminate according
to a second embodiment of the present invention.
FIG. 4 is an enlarged sectional view illustrating a main part of a laminate according
to a third embodiment of the present invention.
FIG. 5 is an enlarged sectional view illustrating a main part of a laminate according
to a fourth embodiment of the present invention.
FIG. 6 is an enlarged sectional view illustrating a main part of a laminate according
to a fifth embodiment of the present invention.
FIG. 7 is an enlarged sectional view illustrating a main part of a laminate according
to a sixth embodiment of the present invention.
FIG. 8 is an enlarged sectional view illustrating a main part of a laminate according
to a seventh embodiment of the present invention.
FIG. 9 is an enlarged sectional view illustrating a main part of a laminate according
to an eighth embodiment of the present invention.
FIG. 10 is an enlarged sectional view illustrating a main part of a laminate according
to a ninth embodiment of the present invention.
FIG. 11 is a table showing results of an evaluation test according to [Example 1].
FIG. 12 is a plan view illustrating a laminate according to a tenth embodiment of
the present invention.
FIG. 13 is a plan view illustrating a laminate according to an eleventh embodiment
of the present invention.
FIG. 14 is a table showing results of an evaluation test according to [Example 2].
FIG. 15 is an explanatory view illustrating a problem inherent in a conventional laminate.
FIG. 16 is a plan view illustrating a laminate according to a twelfth embodiment of
the present invention.
FIG. 17 is a table showing results of an evaluation test according to [Example 3].
FIG. 18 is an explanatory view illustrating a problem inherent in another conventional
laminate.
FIG. 19 is a plan view illustrating a laminate according to a thirteenth embodiment
of the present invention.
FIG. 20 is a table showing results of an evaluation test according to [Example 4].
FIG. 21 is an explanatory view illustrating a cutting method for a laminate according
to a fourteenth embodiment of the present invention.
FIG. 22 is an enlarged sectional view illustrating a state in the vicinity of a laminate
in FIG. 21.
FIG. 23 is a perspective view illustrating a situation in which the laminate is cut
by a cutting apparatus in FIG. 21.
FIG. 24 is an explanatory view illustrating a cutting method for a laminate according
to a fifteenth embodiment of the present invention.
FIG. 25 is an explanatory view illustrating a cutting method for a laminate according
to a sixteenth embodiment of the present invention.
FIG. 26 is an explanatory view illustrating a cutting method for a laminate according
to a seventeenth embodiment of the present invention.
FIG. 27 is an explanatory view illustrating a cutting method for a laminate according
to an eighteenth embodiment of the present invention.
FIG. 28 is an explanatory view illustrating a manufacturing method for a laminate
according to a nineteenth embodiment of the present invention.
FIG. 29a is a schematic side view illustrating a laminate to which a processing method
according to a twentieth embodiment of the present invention is applied.
FIG. 29b is a conceptual view illustrating a first phase of a finishing step of the
processing method according to the twentieth embodiment.
FIG. 29c is a conceptual view illustrating the first phase of the finishing step of
the processing method according to the twentieth embodiment.
FIG. 30a is a conceptual view illustrating a second phase of the finishing step of
the processing method according to the twentieth embodiment.
FIG. 30b is a partial side view illustrating the laminate after completion of the
finishing step of the processing method according to the twentieth embodiment.
FIG. 31a is a conceptual view illustrating a modification example of the first phase
according to the twentieth embodiment.
FIG. 31b is a conceptual view illustrating another modification example of the first
phase according to the twentieth embodiment.
FIG. 32a is a conceptual view illustrating a first phase according to a modification
example of the twentieth embodiment.
FIG. 32b is a conceptual view illustrating a second phase according to the modification
example of the twentieth embodiment.
FIG. 32c is a partial side view illustrating the laminate after completion of the
first phase and the second phase according to the modification example of the twentieth
embodiment.
FIG. 33a is a conceptual view illustrating a first phase according to another modification
example of the twentieth embodiment.
FIG. 33b is a conceptual view illustrating a second phase according to the another
modification example of the twentieth embodiment.
FIG. 33c is a partial side view illustrating the laminate after completion of the
first phase and the second phase according to the another modification example of
the twentieth embodiment.
FIG. 34a is a schematic plan view illustrating a cutting apparatus for a brittle sheet-like
object according to a twenty-first embodiment of the present invention.
FIG. 34b is a schematic sectional view taken on the arrows X-X in FIG. 34a.
FIG. 34c is a schematic plan view illustrating a state in which the brittle sheet-like
object is divided into a product portion and a non-product portion through use of
the cutting apparatus illustrated in FIGS. 34a and 34b.
FIG. 35a is a schematic sectional view illustrating a modification example of a support
member as a component of the cutting apparatus.
FIG. 35b is a schematic sectional view illustrating another modification example of
the support member as the component of the cutting apparatus.
FIG. 36a is an enlarged sectional view illustrating a main part of a cutting apparatus
in a phase in which laser fusing is started according to a modification example of
the twenty-first embodiment.
FIG. 36b is an enlarged sectional view illustrating a main part of the cutting apparatus
immediately before the laser fusing is completed according to the modification example
of the twenty-first embodiment.
FIG. 37 is a schematic plan view illustrating a modification example of a manner of
cutting the brittle sheet-like object according to the twenty-first embodiment.
FIG. 38 is a schematic plan view illustrating another modification example of the
manner of cutting the brittle sheet-like object according to the twenty-first embodiment.
FIG. 39a is an enlarged sectional view illustrating a main part of a conventional
cutting apparatus in a phase in which laser fusing is started.
FIG. 39b is an enlarged sectional view illustrating a main part of the conventional
cutting apparatus immediately before the laser fusing is completed.
Description of Embodiments
[0092] Now, embodiments of the present invention (first to fifth inventions) are described
with reference to the accompanying drawings.
<First Embodiment>
[0093] As illustrated in FIG. 1, a laminate 1 according to a first embodiment of the present
invention comprises a resin sheet 2 and glass sheets 4 that are integrally laminated
on both surfaces of the resin sheet 2 with adhesive layers 3, respectively. For example,
the laminate 1 is used for a cover member of a touch panel of a portable electronic
device. Note that, the adhesive layers 3 may be omitted and the resin sheet 2 may
be adhered directly to the glass sheets 4 by welding or the like. Further, the glass
sheet 4 may be integrally laminated on only one of both surfaces of the resin sheet
2.
[0094] As the resin sheet 2, for example, a resin sheet having a thickness of 0.01 mm or
more and 20 mm or less (preferably 0.01 mm or more and 10 mm or less) is used, and
in the case where the laminate 1 is used for a cover member of a touch panel to be
mounted to a portable electronic device or the like, the thickness of the resin sheet
2 is preferably 0.1 mm or more and 3 mm or less (in particular, 0.1 mm or more and
2 mm or less). As a material for the resin sheet 2, for example, various kinds of
resin material may be used, such as polycarbonate, acrylic, polyethylene terephthalate,
PEEK, polyamide, polyvinyl chloride, polyethylene, polypropylene, and polyethylene
naphthalate. In this case, the resin sheet 2 encompasses a resin film (the same applies
hereinafter).
[0095] As the glass sheet 4, for example, a glass sheet having a thickness of 0.01 mm or
more and 0.7 mm or less is used. In the case where the laminate 1 is used for a cover
member of a touch panel or the like, the thickness of the glass sheet 4 is preferably
0.01 mm or more and 0.5 mm or less, more preferably 0.01 mm or more and 0.3 mm or
less (in particular, 0.01 mm or more and 0.2 mm or less). Note that, it is preferred
that the glass sheet 4 be thinner than the resin sheet 2. As a composition of the
glass sheet 4, various kinds of glass may be used, and alkali-free glass is preferred.
This is because, in the case of glass containing an alkaline component as the composition,
the alkaline component contained in the glass is lost over time, and when a bending
stress is applied to the laminate, the glass sheet is liable to break at a point starting
from the portion in which the alkaline component is lost. In this case, the glass
sheet 4 encompasses a glass film (the same applies hereinafter).
[0096] Note that, the thickness of the adhesive layer 3 is, for example, about 0.001 to
2.0 mm. In the case where the laminate 1 is used for a cover member of a touch panel
or the like, the thickness of the adhesive layer is preferably 0.01 mm or more and
0.5 mm or less, more preferably 0.01 mm or more and 0.3 mm or less, further preferably
0.01 mm or more and 0.1 mm or less. As a material for the adhesive layer 3, for example,
there may be used an acrylic pressure sensitive adhesive, a silicone pressure sensitive
adhesive, a rubber pressure sensitive adhesive, an ultraviolet curable acrylic adhesive,
an ultraviolet curable epoxy adhesive, a thermosetting epoxy adhesive, a thermosetting
melamine adhesive, a thermosetting phenolic adhesive, an ethylene-vinyl acetate (EVA)
interlayer, and a polyvinyl butyral (PVB) interlayer.
[0097] As illustrated in an enlarged view of FIG. 2, the structure of the laminate 1 has
a feature in that an end surface 4a of the glass sheet 4 integrally laminated on the
resin sheet 2 comprises a processed surface obtained by chamfering. Note that, in
the example of FIG. 2, an end surface 2a of the resin sheet 2 is not chamfered.
[0098] Specifically, the end surface 4a of the glass sheet 4 is roundly chamfered (subjected
to round chamfering) into a substantially arc-like shape (for example, an arc corresponding
to a quarter of a circle with a single curvature and an arc corresponding to one-eighth
of a circle with a single curvature). With this structure, an angular portion is cut
off from the end surface 4a of the glass sheet 4. As a result, even when another member
strikes against the end surface 4a of the glass sheet 4, the stress generated in the
end surface 4a of the glass sheet 4 is dispersed and relieved to prevent stress concentration.
Thus, damage to the end surface 4a of the glass sheet 4 and separation between the
glass sheet 4 and the resin sheet 2 can be prevented to the extent possible.
[0099] Next, a manufacturing method for the above-mentioned laminate 1 is described.
[0100] First, the glass sheets 4 are integrally laminated on both surfaces of the resin
sheet 2 through an intermediation of the adhesive layers 3 made of an adhesive. Subsequently,
the end surface 4a of each glass sheet 4 integrally laminated on the resin sheet 2
is chamfered. The chamfering is carried out by mechanically grinding the end surface
4a of the glass sheet 4 with a grinding wheel. In this case, for the glass sheet 4
having a thickness of 300 µm or less alone, when the end surface 4a is mechanically
ground with the grinding wheel, damages such as chipping and breaking are liable to
occur in the end surface 4a of the glass sheet 4. In contrast, in the above-mentioned
manufacturing method, the glass sheet 4 is reinforced with the resin sheet 2, and
then the end surface 4a of the glass sheet 4 is chamfered. Thus, the end surface 4a
of the glass sheet 4 can be mechanically ground with the grinding wheel while preventing
the damage to the glass sheet 4.
[0101] In this case, as the method of chamfering the end surface 4a of the glass sheet 4
other than the above-mentioned method, for example, there may be employed a method
that involves stacking a plurality of glass sheets 4 having a thickness of 300 µm
or less, adhering their surfaces to each other (into close contact with each other)
through optical contact without using the adhesive, and chamfering, in this lamination
state, the end surface of each glass sheet 4 with the grinding wheel. In this case,
a surface roughness Ra of the surface of the glass sheet 4 on the close-contact portion
side is preferably 2.0 nm or less, particularly preferably 0.2 nm or less. With this
structure, each glass sheet 4 is reinforced with the other glass sheets 4, and hence
the glass sheet 4 can be prevented from being damaged at the time of chamfering. In
this case, the glass sheets 4 subjected to the chamfering are integrally laminated
on the resin sheet 2 with an adhesive or the like.
[0102] Further, instead of the mechanical grinding with the grinding wheel, the end surface
4a of the glass sheet 4 may be immersed into an etchant such as a hydrofluoric acid
to chamfer the edge portion of the end surface 4a of the glass sheet 4. In this case,
the glass sheet 4 subjected to the chamfering is integrally laminated on the resin
sheet 2 with an adhesive or the like. As a matter of course, after the glass sheet
4 is integrally laminated on the resin sheet 2 with an adhesive or the like, the end
surface of the laminate may be immersed into an etchant such as a hydrofluoric acid
or applied with a plasma of a compound containing fluorine (for example, carbon tetrafluoride),
to thereby chamfer the edge portion of the end surface 4a of the glass sheet 4.
[0103] In the above description, the laminate to be used for a protective cover of a touch
panel is taken as an example, and as a matter of course, the present invention is
also applicable to a laminate to be built into panels of various electric or electronic
devices as typified by flat panel displays (FPDs), induction cookers, and solar cells,
and further to a laminate to be built into window panels of building structures and
various vehicles. Note that, the same applies hereinafter for the use of the laminate
described above.
<Second Embodiment>
[0104] As illustrated in FIG. 3, a laminate 1 according to a second embodiment of the present
invention is different from the laminate 1 according to the first embodiment in that
the edge portion of the end surface 4a of the glass sheet 4 is cut off along a straight
line (C-chamfering).
[0105] Specifically, the end surface 4a of the glass sheet 4 is chamfered by cutting off,
along the straight line, an edge portion (triangular portion) formed at a part connecting
the end surface 4a of the glass sheet 4 and a surface of the glass sheet 4 on an outermost
surface side (side on which the resin sheet 2 is not located) while a surface extending
in a direction substantially perpendicular to the surface of the glass sheet 4 is
left in the end surface 4a of the glass sheet 4. In this case, the angle formed at
the part connecting the end surface 4a of the glass sheet 4 and the surface of the
glass sheet 4 serving as the outermost surface is set to more than 90° (preferably
120° or more).
[0106] Note that, FIG. 3 illustrates the case where the edge portion of the end surface
4a of the glass sheet 4 is cut off along the straight line in such a manner that the
surface extending in the direction substantially perpendicular to the surface of the
glass sheet 4 is left in the end surface 4a of the glass sheet 4, but the edge portion
of the end surface 4a of the glass sheet 4 may be cut off along the straight line
in such a manner that the surface extending in the substantially perpendicular direction
is not left. In other words, the end surface 4a of the glass sheet 4 may be formed
only of a tapered surface.
<Third Embodiment>
[0107] As illustrated in FIG. 4, a laminate 1 according to a third embodiment of the present
invention is different from the laminates 1 according to the first and second embodiments
in that the end surface 4a of the glass sheet 4 is chamfered into composite flat surfaces
obtained by connecting a plurality of tapered surfaces having different inclination
angles.
<Fourth Embodiment>
[0108] As illustrated in FIG. 5, a laminate 1 according to a fourth embodiment of the present
invention is different from the laminates 1 according to the first to third embodiments
in that the chamfering is carried out continuously over a range from the end surface
4a of the glass sheet 4 to the end surface 2a of the resin sheet 2.
[0109] Specifically, in this embodiment, the end surface 4a of the glass sheet 4 and the
end surface 2a of the resin sheet 2 are chamfered continuously into a single arc surface.
Note that, the single arc surface encompasses the shapes of not only a perfect circle
but also a non-perfect circle such as an ellipse and a parabola.
<Fifth Embodiment>
[0110] As illustrated in FIG. 6, a laminate 1 according to a fifth embodiment of the present
invention is different from the laminates 1 according to the first to fourth embodiments
in that the end surface 2a of the resin sheet 2 protrudes with respect to the end
surface 4a of the glass sheet 4.
[0111] Specifically, in this embodiment, the entire end surface 4a of the glass sheet 4
is chamfered into an inclined surface, and the entire end surface 2a of the resin
sheet 2 protrudes from a distal end of the end surface 4a of the glass sheet 4. Note
that, the end surface 2a of the resin sheet 2 is not chamfered.
[0112] A protruding dimension δ1 of the end surface 2a of the resin sheet 2 with respect
to the end surface 4a of the glass sheet 4 is set to, for example, about 0.01 to 5
mm. It is preferred that the protruding dimension δ1 be determined in consideration
of a thermal expansion coefficient of the resin sheet 2 or a difference in thermal
expansion between the resin sheet 2 and the glass sheet 4 and the areas of the flat
surfaces of the resin sheet 2 and the glass sheet 4.
[0113] With this structure, even if there occurs such a situation that another member is
brought into contact with the end surface of the laminate 1, the another member is
preferentially brought into contact with the end surface 2a of the resin sheet 2 that
protrudes with respect to the end surface 4a of the glass sheet 4, and hence the another
member is not easily brought into direct contact with the end surface of the glass
sheet 4. As a result, the damage to the end surface 4a of the glass sheet 4 and the
separation between the glass sheet 4 and the resin sheet 2 can be prevented more reliably.
Note that, this effect can be produced, despite some differences, as long as at least
a part of the end surface 2a of the resin sheet 2 protrudes with respect to the end
surface 4a of the glass sheet 4. That is, a similar effect can be produced also in
the case where the region ranging from the end surface 4a of the glass sheet 4 to
the end surface 2a of the resin sheet 2 is chamfered continuously into a substantially
arc-like shape as in the manner described in the fifth embodiment.
[0114] Note that, in the case where at least a part (preferably the entire region) of the
end surface 2a of the resin sheet 2 protrudes with respect to the end surface 4a of
the glass sheet 4 in the manner described above, the chamfering of the end surface
4a of the glass sheet 4 may be omitted as appropriate.
[0115] Further, the end surface of the adhesive layer 3 may be located on the same plane
as that of the end surface 4a of the glass sheet 4, or may protrude from the end surface
4a of the glass sheet 4. In the latter case, the adhesive layer 3 can reliably act
on a region including the edge of the end surface 4a of the glass sheet 4, which is
also suitable to prevent the separation of the glass sheet 4. In this case, the adhesive
layer 3 extending beyond the end surface 4a of the glass sheet 4 may be routed toward
the end surface 4a of the glass sheet 4 so that the adhesive layer 3 covers at least
a part of the end surface 4a of the glass sheet 4.
<Sixth Embodiment>
[0116] As illustrated in FIG. 7, a laminate 1 according to a sixth embodiment of the present
invention is different from the laminate 1 according to the fifth embodiment in that
the end surface 4a of the glass sheet 4 is chamfered into composite curved surfaces
obtained by connecting a plurality of arc surfaces having different curvatures.
<Seventh Embodiment>
[0117] As illustrated in FIG. 8, a laminate 1 according to a seventh embodiment of the present
invention is different from the laminates 1 according to the fifth and sixth embodiments
in that the end surface 4a of the glass sheet 4 is chamfered into a single arc surface
(for example, an arc corresponding to a quarter of a circle and an arc corresponding
to one-eighth of a circle). Note that, the single arc surface encompasses the shapes
of not only a perfect circle but also a non-perfect circle such as an ellipse and
a parabola.
<Eighth Embodiment>
[0118] As illustrated in FIG. 9, a laminate 1 according to an eighth embodiment of the present
invention is different from the laminates 1 according to the fifth to seventh embodiments
in that the edge portion of the end surface 4a of the glass sheet 4 is cut off along
a straight line (C-chamfering).
[0119] Specifically, the end surface 4a of the glass sheet 4 is chamfered by cutting off,
along the straight line, an edge portion (triangular portion) formed at a part connecting
the end surface 4a of the glass sheet 4 and a surface of the glass sheet 4 on an outermost
surface side (side on which the resin sheet 2 is not located) while a surface extending
in a direction substantially perpendicular to the surface of the glass sheet 4 is
left in the end surface 4a of the glass sheet 4.
[0120] Note that, FIG. 9 illustrates the case where the edge portion of the end surface
4a of the glass sheet 4 is cut off along the straight line in such a manner that the
surface extending in the direction substantially perpendicular to the surface of the
glass sheet 4 is left in the end surface 4a of the glass sheet 4, but the edge portion
of the end surface 4a of the glass sheet 4 may be cut off along the straight line
in such a manner that the surface extending in the substantially perpendicular direction
is not left. In other words, the end surface 4a of the glass sheet 4 may be formed
only of a tapered surface.
<Ninth Embodiment>
[0121] As illustrated in FIG. 10, a laminate 1 according to a ninth embodiment of the present
invention is different from the laminates 1 according to the fifth to eighth embodiments
in that the chamfering is carried out continuously over a range from the end surface
4a of the glass sheet 4 to the end surface 2a of the resin sheet 2.
[0122] Specifically, in this embodiment, the region ranging from the end surface 4a of the
glass sheet 4 to the end surface 2a of the resin sheet 2 is chamfered into a single
inclined surface.
Example 1
[0123] Description is given of an example of results of an evaluation test obtained in a
case where the end surface of the glass sheet of the laminate was chamfered and in
a case where the end surface of the glass sheet of the laminate was not chamfered.
[0124] In this evaluation test, another member was brought into contact with an end surface
of each of laminates according to Examples 1 to 5 and a laminate according to Comparative
Example 1 so as to inspect whether or not chipping or separation occurred in the glass
sheet.
[0125] The basic structure of the laminates according to Examples 1 to 5 and the laminate
according to Comparative Example 1 is as follows. That is, the laminates according
to the examples and the laminate according to the comparative example are both formed
by adhering glass sheets to both surfaces of a resin sheet. Each glass sheet is made
of alkali-free glass (OA-10G manufactured by Nippon Electric Glass Co., Ltd.), and
has a thickness of 0.1 mmt and plane dimensions of 100 mm×100 mm in Examples 1 and
3 and Comparative Example 1, 99.5×99.5 mm in Example 2, and 99 mm×99 mm in Examples
4 and 5. The resin sheet is made of polycarbonate, and has dimensions of 100 mm×100
mm×1 mmt. Further, the glass sheets are integrally laminated on the resin sheet with
adhesive layers. Each adhesive layer is made of an acrylic pressure sensitive adhesive,
and has a thickness of 0.025 mmt.
[0126] As test conditions for the evaluation test, the end surface of the laminate is brought
into contact with waterproof sand paper (#320) of a grinding machine (Knuth Rotor)
at a contact angle of 60° with a load of 2 N for one second. This evaluation test
is conducted on both surfaces of four edges of the laminate. That is, the evaluation
test is conducted on a single laminate eight times in total. Under those conditions,
chipping portions of 50 µm or more and separating portions that were generated in
the end surface of the glass sheet of the laminate were counted. FIG. 11 shows results
thereof.
[0127] Referring to FIG. 11, it can be found that Examples 1 to 5, in which the end surface
of the glass sheet was chamfered, produced satisfactory results, specifically, the
chipping and the separation were reduced more greatly than in Comparative Example
1, in which the end surface of the glass sheet was not chamfered. Further, it can
be said that the structure in which the end surface of the resin sheet protrudes with
respect to the end surface of the glass sheet as in Examples 4 and 5 is particularly
preferred from the viewpoint of preventing the chipping and the separation.
<Tenth Embodiment>
[0128] A laminate according to a tenth embodiment of the present invention is in common
with the laminates according to the above-mentioned first to ninth embodiments in
that the glass sheet having a thickness of 300 µm or less is integrally laminated
on at least one of both surfaces of the resin sheet, and the laminate according to
the tenth embodiment is different from the laminates according to the first to ninth
embodiments in the following matters.
[0129] That is, as illustrated in FIG. 12, corners of a laminate 1 according to the tenth
embodiment are chamfered so that edge portions of corner portions 1a of the laminate
1 are formed into a substantially arc-like shape. With this structure, the corner
portions 1a of the laminate 1 do not have an acute angle of 90° or less, with the
result that the stress concentration that may occur in the corner portions 1a due
to the difference in thermal expansion between the glass sheet 4 and the resin sheet
2 is relieved and the separation does not easily occur.
[0130] Note that, in the laminate 1 according to the tenth embodiment, at least the end
surface 4a of the glass sheet 4 is chamfered. Specifically, the end surface of the
laminate 1 has, for example, any one of the shapes as described above with reference
to FIGS. 2 to 10.
[0131] The laminate 1 described above is, for example, manufactured in the following manner.
That is, first, the glass sheets 4 are integrally laminated on both surfaces of the
resin sheet 2 through an intermediation of the adhesive layers 3 made of an adhesive.
Subsequently, the corner portions 1a of the laminate 1 obtained by integrally laminating
the glass sheets 4 on the resin sheet 2 are chamfered. The corner chamfering is carried
out by mechanically grinding the corner portions 1a of the laminate 1 with the grinding
wheel. Note that, when grinding the corner portions 1a of the laminate 1, the corner
portions of the glass sheet 4 and the corresponding corner portions of the resin sheet
2 are ground at the same time. As a matter of course, the corner portions of the glass
sheet 4 and the corresponding corner portions of the resin sheet 2 may be ground independently.
<Eleventh Embodiment>
[0132] As illustrated in FIG. 13, a laminate 1 according to an eleventh embodiment of the
present invention is different from the laminate 1 according to the tenth embodiment
in that the corner portions 1a of the laminate 1 are chamfered into a polygonal shape
obtained by combining obtuse angles (preferably 120° or more).
Example 2
[0133] Description is given of an example of results of an evaluation test obtained in a
case where the corner portions of the laminate have a polygonal shape or a curved
shape and in a case where the corner portions of the laminate form a substantially
right angle.
[0134] In this evaluation test, laminates according to Examples 6 and 7 and a laminate according
to Comparative Example 2 were cooled after heating so as to inspect whether or not
separation occurred in each laminate.
[0135] The basic structure of the laminates according to Examples 6 and 7 and the laminate
according to Comparative Example 2 is as follows. That is, the laminates according
to the examples and the laminate according to the comparative example are both formed
by adhering glass sheets to both surfaces of a resin sheet. Each glass sheet is made
of alkali-free glass (OA-10G manufactured by Nippon Electric Glass Co., Ltd.), and
has a thermal expansion coefficient of 38×10
-7/°C and dimensions of 500 mm×500 mm×0.1 mmt. The resin sheet is made of polycarbonate,
and has a thermal expansion coefficient of 70×10
-6/°C and dimensions of 500 mm×500 mm×1 mmt. Further, the glass sheets are integrally
laminated on the resin sheet with adhesive layers. Each adhesive layer is made of
an ultraviolet curable acrylic adhesive, and has dimensions of 500 mm×500 mm×0.01
mmt. The corner portions of the laminate according to Example 6 are chamfered at a
curvature radius of 10 mm. The corner portions of the laminate according to Example
7 are chamfered into a polygonal shape obtained by combining three obtuse angles (160°,
130°, and 160° in an order from one edge side of the laminate), and the chamfered
corner portions have dimensions of 10 mm×10 mm. In contrast, the corner portions of
the laminate according to Comparative Example 2 are not chamfered.
[0136] As test conditions for the evaluation test, the temperature of the laminate was raised
from room temperature to 90°C at a rate of 1°C/min, and was maintained at 90°C for
two hours. After that, the temperature of the laminate was dropped down to -40°C at
a rate of -1°C/min, and was maintained at -40°C for two hours. Then, the temperature
of the laminate was raised again up to 90°C at a rate of 1°C/min, and was maintained
at 90°C for two hours. This temperature cycle was carried out 20 times, and the temperature
of the laminate was finally dropped from 90°C to room temperature at a rate of -1°C/min.
Through the heating and cooling of the laminate under those temperature conditions,
the presence and absence of the separation was inspected. FIG. 14 shows results thereof.
[0137] Referring to FIG. 14, it can be found that Examples 6 and 7, in which the corner
portions of the laminate were chamfered, produced satisfactory results, specifically,
the separation was reduced more greatly than in Comparative Example 2, in which the
corner portions were not chamfered. Further, the structure in which the corner portions
of the laminate have a substantially arc-like shape as in Example 6 is particularly
preferred because the effect of relieving the stress concentration becomes greater.
<Twelfth Embodiment>
[0138] A laminate according to a twelfth embodiment of the present invention is in common
with the laminates according to the above-mentioned embodiments in that the glass
sheet is integrally laminated on at least one of both surfaces of the resin sheet,
and the laminate according to the twelfth embodiment is different from the laminates
according to the above-mentioned embodiments in following matters.
[0139] That is, as illustrated in FIG. 15, the laminate 1 may comprise a depressed portion
5 and a projecting portion 6 formed at an outer peripheral part thereof. Further,
when bending portions 5a and 6a formed by crossing straight lines (for example, two
straight lines orthogonal to each other) are located in a region in which the depressed
portion 5 and the projecting portion 6 are formed, in a case where a significant temperature
change occurs in a surrounding environment of the laminate 1 (for example, in a case
where the temperature of the surrounding environment of the laminate 1 is raised from
20°C to 80°C), the tensile stress acting on the glass sheet 4 due to the difference
in thermal expansion between the glass sheet 4 and the resin sheet 2 concentrates
on the bending portions 5a and 6a, thus leading to a problem in that the glass sheet
4 is liable to be damaged.
[0140] Therefore, as illustrated in FIG. 16, a laminate 1 according to the twelfth embodiment
comprises a depressed portion 5 formed at one of two opposing edges of the laminate
1 on an outer periphery thereof, and a projecting portion 6 formed at another of the
two opposing edges. Corners corresponding to bending portions 5a of the depressed
portion 5 and corners corresponding to bending portions 6a of the projecting portion
6 are chamfered into a continuous arc-like shape (curved shape). With this structure,
the bending portions 5a formed in the depressed portion 5 of the laminate 1 and the
bending portions 6a formed in the projecting portion 6 of the laminate 1 do not have
an acute angle. Therefore, the concentration of the tensile stress acting on the bending
portions of the glass sheet 4 due to the difference in thermal expansion between the
glass sheet 4 and the resin sheet 2 is relieved, and the glass sheet 4 is not easily
damaged. In this case, the curvature radius of the bending portions 5a and 6a is preferably
0.5 mm or more, further preferably 1 mm or more.
Example 3
[0141] Description is given of an example of results of an evaluation test obtained in a
case where the bending portions of the deformed portion formed of the depressed portion
(or the projecting portion) formed on the outer periphery of the laminate have a curved
shape and in a case where the bending portions of the deformed portion do not have
a curved shape.
[0142] In this evaluation test, a laminate according to Example 8 and laminates according
to Comparative Examples 3 and 4 were cooled after heating so as to inspect whether
or not breaking occurred in each glass sheet.
[0143] The basic structure of the laminate according to Example 8 and the laminates according
to Comparative Examples 3 and 4 is as follows. That is, the laminate according to
the example and the laminates according to the comparative examples are both formed
by adhering glass sheets to both surfaces of a resin sheet. Each laminate comprises
a depressed portion of 30 mm (short side direction)×10 mm (long side direction) at
a center portion of the short side. Each glass sheet is made of alkali-free glass
(OA-10G manufactured by Nippon Electric Glass Co., Ltd.), and has a thermal expansion
coefficient of 38×10
-7/°C and dimensions of 50 mm×100 mm×0.1 mmt. The resin sheet is made of polycarbonate,
and has a thermal expansion coefficient of 70×10
-6/°C and dimensions of 50 mm×100 mm×1 1 mmt. Further, the glass sheets are integrally
laminated on the resin sheet with adhesive layers. Each adhesive layer is made of
an ultraviolet curable acrylic adhesive, and has dimensions of 50 mm×100 mm×0.01 mmt.
The corners corresponding to bending portions formed in the depressed portion of the
laminate according to Example 8 are chamfered into an arc-like shape at a curvature
radius of 2 mm. The corners corresponding to bending portions formed in the depressed
portion of the laminate according to Comparative Example 3 are not chamfered. The
corners corresponding to bending portions formed in the depressed portion of the laminate
according to Comparative Example 4 are chamfered into a polygonal shape obtained by
combining two obtuse angles (each 225°), and the chamfered corner portions have dimensions
of 2 mm×2 mm.
[0144] As test conditions for the evaluation test, the temperature of the laminate was raised
from room temperature to 90°C at a rate of 1°C/min, and was maintained at 90°C for
two hours. After that, the temperature of the laminate was dropped down to -40°C at
a rate of -1°C/min, and was maintained at -40°C for two hours. Then, the temperature
of the laminate was raised again up to 90°C at a rate of 1°C/min, and was maintained
at 90°C for two hours. This temperature cycle was carried out 20 times, and the temperature
of the laminate was finally dropped from 90°C to room temperature at a rate of -1°C/min.
Through the heating and cooling of the laminate under those temperature conditions,
the presence and absence of the breaking in each glass sheet was inspected. FIG. 17
shows results thereof.
[0145] As shown in FIG. 17, Example 8, in which the corners corresponding to the bending
portions formed in the depressed portion of the laminate were chamfered into a substantially
arc-like shape, produced satisfactory results, specifically, the breaking of the glass
sheet was reduced more reliably than in Comparative Examples 3 and 4, in which the
bending portions formed by crossing straight lines were left in the depressed portion.
Note that, the same results are obtained for the bending portions of the projecting
portion.
<Thirteenth Embodiment>
[0146] A laminate according to a thirteenth embodiment of the present invention is in common
with the laminates according to the above-mentioned embodiments in that the glass
sheet is integrally laminated on at least one of both surfaces of the resin sheet,
and the laminate according to the thirteenth embodiment is different from the laminates
according to the above-mentioned embodiments in following matters.
[0147] That is, as illustrated in FIG. 18, the laminate 1 may comprise an opening portion
7 having a substantially rectangular shape portion formed in a flat surface thereof.
Further, when bending portions 7a formed by crossing straight lines (for example,
two straight lines orthogonal to each other) are located in a region in which the
opening portion 7 is formed, in a case where a significant temperature change occurs
in a surrounding environment of the laminate 1 (for example, in a case where the temperature
of the surrounding environment of the laminate is raised from 20°C to 80°C), the tensile
stress acting on the glass sheet 4 due to the difference in thermal expansion between
the glass sheet 4 and the resin sheet 2 concentrates on the bending portions 7a so
that the glass sheet 4 is liable to be damaged.
[0148] Therefore, as illustrated in FIG. 19, corners of a laminate 1 according to the thirteenth
embodiment are chamfered so that the bending portions 7a of the opening portion 7
formed in a flat surface of the laminate 1 are formed into a continuous arc-like shape
(curved shape). With this structure, the bending portions 7a formed in the opening
portion 7 of the laminate 1 do not have an acute angle. Therefore, the concentration
of the tensile stress acting on the bending portions of the glass sheet 4 due to the
difference in thermal expansion between the glass sheet 4 and the resin sheet 2 is
relieved, and the glass sheet 4 is not easily damaged. In this case, the curvature
radius of the bending portions 7a is preferably 0.5 mm or more, further preferably
1 mm or more.
Example 4
[0149] Description is given of an example of results of an evaluation test obtained in a
case where the bending portions formed in the opening portion of the laminate have
a curved shape and in a case where the bending portions formed in the opening portion
do not have a curved shape.
[0150] In this evaluation test, laminates according to Examples 9 and 10 and laminates according
to Comparative Examples 5 and 6 were cooled after heating so as to inspect whether
or not breaking occurred in each glass sheet.
[0151] The basic structure of the laminates according to Examples 9 and 10 and the laminate
according to Comparative Examples 5 and 6 is as follows. That is, the laminates according
to the examples and the laminate according to the comparative examples are both formed
by adhering glass sheets to both surfaces of a resin sheet. Each laminate comprises
an opening portion of 30 mm (short side direction)×10 mm (long side direction) at
a center portion thereof. (The center point of the contour of the outer periphery
of the laminate matches with the center point of the contour of the opening portion.)
Each glass sheet is made of alkali-free glass (OA-10G manufactured by Nippon Electric
Glass Co., Ltd.), and has a thermal expansion coefficient of 38×10
-7/°C and dimensions of 50 mm×100 mm×0.1 mmt. The resin sheet is made of polycarbonate,
and has a thermal expansion coefficient of 70×10
-6/°C and dimensions of 50 mm×100 mm×1 mmt. Further, the glass sheets are integrally
laminated on the resin sheet with adhesive layers. Each adhesive layer is made of
an ultraviolet curable acrylic adhesive, and has dimensions of 50 mm×100 mm×0.01 mmt.
The corners corresponding to bending portions formed in the opening portion of the
laminate according Example 9 are chamfered into an arc-like shape at a curvature radius
of 2 mm. The corners corresponding to bending portions formed in the opening portion
of the laminate according Example 10 are chamfered into an arc-like shape at a curvature
radius of 5 mm. The corners corresponding to bending portions formed in the opening
portion of the laminate according to Comparative Example 5 are not chamfered. The
corners corresponding to bending portions formed in the opening portion of the laminate
according to Comparative Example 6 are chamfered into a polygonal shape obtained by
combining two obtuse angles (each 225°), and the chamfered corner portions have dimensions
of 2 mm×2 mm.
[0152] As test conditions for the evaluation test, the temperature of the laminate was raised
from room temperature to 90°C at a rate of 1°C/min, and was maintained at 90°C for
two hours. After that, the temperature of the laminate was dropped down to -40°C at
a rate of -1°C/min, and was maintained at -40°C for two hours. Then, the temperature
of the laminate was raised again up to 90°C at a rate of 1°C/min, and was maintained
at 90°C for two hours. This temperature cycle was carried out 20 times, and the temperature
of the laminate was finally dropped from 90°C to room temperature at a rate of -1°C/min.
Through the heating and cooling of the laminate under those temperature conditions,
the presence and absence of the breaking in each glass sheet was inspected. FIG. 20
shows results thereof.
[0153] As shown in FIG. 20, Examples 9 and 10, in which the corners corresponding to the
bending portions formed in the opening portion of the laminate were chamfered into
a substantially arc-like shape, produced satisfactory results, specifically, the breaking
of the glass sheet was reduced more reliably than in Comparative Examples 5 and 6,
in which the bending portions formed by crossing straight lines were left in the opening
portion.
<Fourteenth Embodiment>
[0154] A fourteenth embodiment of the present invention relates to a cutting method for
a laminate obtained by integrally laminating glass sheets on both surfaces of a resin
sheet. This cutting method is used for cutting the above-mentioned laminate 1 into
a predetermined shape and dimensions.
[0155] FIG. 21 is a view illustrating a cutting apparatus for implementing the cutting method
for a laminate according to the fourteenth embodiment. A cutting apparatus 10 of this
embodiment is configured to carry out laser fusing on the laminate 1, and comprises
a laser irradiation apparatus 11 for radiating a laser beam LB, and support stages
14 for supporting the laminate 1. Note that, in this embodiment, the laminate 1 is
irradiated with the laser beam LB from the top of the laminate 1. That is, an upper
surface of the laminate 1 corresponds to an incident side of the laser beam LB, and
a lower surface of the laminate 1 corresponds to a non-incident side of the laser
beam LB.
[0156] The laser irradiation apparatus 11 has an internal space for propagating the laser
beam LB, and comprises a lens 12 for condensing the laser beam LB, and a gas jet nozzle
13 for jetting an assist gas AG.
[0157] As the laser beam LB, for example, a carbon dioxide laser and a YAG laser may be
used, and the laser beam LB may be continuous light and pulsed light.
[0158] The lens 12 is arranged in the internal space of the laser irradiation apparatus
11, and is configured to condense the laser beam LB so as to form a focal point FP
inside the laminate 1. To give an additional remark, the laser irradiation apparatus
11 is raised and lowered with respect to the laminate 1, to thereby adjust the position
of the focal point FP. Note that, the lens 12 may be arranged outside the laser irradiation
apparatus 5.
[0159] The gas jet nozzle 13 is connected to a distal end portion of the laser irradiation
apparatus 11, and is configured to supply the assist gas AG to the internal space
of the laser irradiation apparatus 11 (space below the lens 12). The assist gas AG
supplied to the internal space of the laser irradiation apparatus 11 is jetted directly
downward (in a substantially perpendicular direction) from the distal end of the laser
irradiation apparatus 11 toward the laminate 1. That is, the laser beam LB is emitted
and the assist gas AG is jetted from the distal end of the laser irradiation apparatus
11. The assist gas AG serves to remove molten foreign matter, which is generated when
the laminate 1 is fused, from the cut portion of the laminate 1, to protect the optical
components such as the lens 12 of the laser irradiation apparatus 11 from the molten
foreign matter, and further to cool the lens 12 so as to remove heat therefrom.
[0160] Note that, the kind of the assist gas AG is not particularly limited, and for example,
a publicly known gas such as an oxygen gas, a water vapor, a carbon dioxide gas, a
nitrogen gas, and an argon gas is used alone or a plurality of kinds of those gases
are used in combination. The assist gas AG may be jetted as a hot gas. The assist
gas AG (gas jet nozzle 13) may be omitted as appropriate.
[0161] The laminate 1 to be cut is obtained by integrally laminating the glass sheets 4
on both surfaces of the resin sheet 2 with the adhesive layers 3, respectively. Note
that, the adhesive layers 3 may be omitted as appropriate.
[0162] Next, description is given of the cutting method for the laminate 1 through use of
the cutting apparatus structured as described above.
[0163] First, as illustrated in FIG. 22, the focal point FP of the laser beam LB radiated
from the laser irradiation apparatus 11 is adjusted inside the laminate 1. A distance
"d" of the focal point FP from the incident side (upper surface side) of the laser
beam LB is set within a range of more than 50% and 90% or less of an overall thickness
of the laminate 1 (preferably 60% or more and 80% or less). Note that, in this embodiment,
the position of the focal point FP is located inside the resin sheet 2 of the laminate
1.
[0164] Subsequently, under a state in which this positional relationship is maintained,
as illustrated in FIG. 23, the laser irradiation apparatus 11 is moved in a scanning
manner with respect to the laminate 1 to fuse and cut the laminate 1 into a desired
shape and dimensions. Note that, when the laser irradiation apparatus 11 and the laminate
1 move relative to each other, any of the laser irradiation apparatus 11 and the laminate
1 may be moved.
[0165] At this time, laser power and laser scanning speed are adjusted so that a value of
(laser power)/(laser scanning speed) becomes 0.001 to 1 (preferably 0.01 to 0.1) W·min/mm.
Note that, the laser power is, for example, 1 to 100 W, and the laser scanning speed
is, for example, 100 to 10,000 mm/min.
[0166] With this method, the position of the focal point FP of the laser beam LB is located
closer to a lower side with respect to a center position of the laminate 1 in the
thickness direction, and hence a sufficient amount of heat is also transferred to
the lower glass sheet 4 side. Thus, the lower glass sheet 4 can also be cut accurately
without hindering the propagation of the laser beam LB inappropriately due to the
molten foreign matter generated at the time of fusing.
Example 5
[0167] Next, description is given of an example of results of an evaluation test for laminates
according to examples of the present invention.
[0168] In this evaluation test, laminates according to Examples 11 to 13 and laminates according
to Comparative Examples 7 to 9 were subjected to laser fusing under predetermined
conditions, and the maximum size of cracks generated in the end surface of the glass
sheet at this time was inspected. Note that, the laser fusing was carried out through
use of a carbon dioxide laser.
[0169] The basic structure of the laminates according to Examples 11 to 13 and the laminates
according to Comparative Examples 7 to 9 is as follows. That is, the laminates according
to the examples and the laminates according to the comparative examples are both formed
by adhering glass sheets to both surfaces of a resin sheet. Each glass sheet is made
of alkali-free glass (OA-10G manufactured by Nippon Electric Glass Co., Ltd.), and
has a thermal expansion coefficient of 38×10
-7/°C and dimensions of 200 mm×200 mm. The resin sheet is made of polycarbonate, and
has dimensions of 200 mm×200 mm. Further, the glass sheets are integrally laminated
on the resin sheet with adhesive layers. Each adhesive layer is made of an acrylic
pressure sensitive adhesive, and has dimensions of 200 mm×200 mm×0.025 mmt.
[0170] As test conditions for the evaluation test, each laminate was irradiated with a laser
beam from the top of the laminate to carry out the laser fusing, and thus the laminate
was trimmed so that the size became 150 mm×150 mm and the curvature radius of each
corner portion formed by crossing two orthogonal edges became 10 mm. Then, the maximum
size of the depth of cracks generated in the end surface of the glass sheet was measured.
Table 1 shows results thereof. Note that, the maximum size of the crack depth that
exceeds 0.2 mm causes damage to the glass sheet.
[Table 1]
|
Example 11 |
Example 12 |
Example 13 |
Comparative Example 7 |
Comparative Example 8 |
Comparative Example 9 |
Thickness of glass sheet (mm) |
0.1 |
0.1 |
0.1 |
0.1 |
0.1 |
0.1 |
Thickness of resin sheet (mm) |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
0.8 |
Thickness of adhesive layer (mm) |
0.025 |
0.025 |
0.025 |
0.025 |
0.025 |
0.025 |
Laser power (W) |
15 |
15 |
15 |
15 |
15 |
15 |
Moving speed (mm/min) |
400 |
400 |
400 |
400 |
400 |
400 |
Laser power/moving speed (W·min/mm) |
0.0375 |
0.0375 |
0.0375 |
0.0375 |
0.0375 |
0.0375 |
Position of focal point (mm)* |
0.6 |
0.7 |
0.8 |
0.05 |
0.5 |
9.95 |
Fusing |
Possible |
Possible |
Possible |
Possible |
Possible |
Possible |
Upper surface glass sheet |
Crack depth (mm) |
0.1 |
0.1 |
0.13 |
0.04 |
0.1 |
0.24 |
Lower surface glass sheet |
Crack depth (mm) |
0.16 |
0.12 |
0.11 |
0.22 |
0.2 |
0.08 |
*Depth from glass surface on upper surface side of laminate |
[0171] It can be found also from Table 1 that the crack depth of the glass sheet of the
fused laminate is smaller in Examples 11 to 13 than in Comparative Examples 7 to 9.
[0172] That is, in a case where the position of the focal point of the laser beam is not
more than 50% and 90% or less of the overall thickness of the laminate as in Comparative
Examples 7 to 9, the crack depth of the glass sheet is larger than 0.2 mm, which causes
damage to the glass sheet. In contrast, in Examples 11 to 13, the position of the
focal point of the laser beam was restricted to fall within the above-mentioned numerical
range, with the result that the crack depth of the glass sheet became smaller and
the crack depth exceeding 0.2 mm that might cause damage to the glass sheet was not
generated.
[0173] Note that, in the above-mentioned examples, it is preferred that the edge portion
of the fused surface of the glass sheet of the laminate be chamfered after the laser
fusing.
<Fifteenth Embodiment>
[0174] In the case where the laminate 1 is subjected to the laser fusing, it is preferred
to adjust the position of the focal point FP of the laser beam LB as in the fourteenth
embodiment, but the laminate 1 may be cut in the following manner.
[0175] That is, as illustrated in FIG. 24, a laser beam L1 may be radiated twice at the
same position. In addition, a position P1 of the focal point at the time of the first
irradiation with the laser beam L1 may be set at a middle position in the thickness
direction of the glass sheet 4 that is located on the laser irradiation side, and
a position P2 of the focal point at the time of the second irradiation with the laser
beam L1 may be set at a middle position in the thickness direction of the glass sheet
4 that is located on the other side.
<Sixteenth Embodiment>
[0176] Further, for example, in a case where the resin sheet 2 is relatively thicker, as
illustrated in FIG. 25, the laser beam L1 may be radiated three times at the same
position. In addition, the position P1 of the focal point at the time of the first
irradiation with the laser beam L1 may be set at the middle position in the thickness
direction of the glass sheet 4 that is located on the laser irradiation side, the
position P2 of the focal point at the time of the second irradiation with the laser
beam L1 may be set at a middle position in the thickness direction of the resin sheet
2, and a position P3 of the focal point at the time of the third irradiation with
the laser beam L1 may be set at the middle position in the thickness direction of
the glass sheet 4 that is located on the other side.
<Seventeenth Embodiment>
[0177] Further, for example, in a case where the glass sheets 4 and the resin sheet 2 are
relatively thicker, as illustrated in FIG. 26, the laser beam L1 may be radiated five
times at the same position. In addition, positions P1 to P5 of the focal point of
the laser beam may be defined by shifting the focal point between the laser irradiation
side and the opposite side so that the positions P1 and P2 of the focal point at the
time of the first and second irradiation with the laser beam L1 are set at the middle
positions in the thickness direction of the glass sheet 4 that is located on the laser
irradiation side, that the position P3 of the focal point at the time of the third
irradiation with the laser beam L1 is set the middle position in the thickness direction
of the resin sheet 2, and that the positions P4 and P5 of the focal point at the time
of the fourth and fifth irradiation with the laser beam L1 are set at the middle positions
in the thickness direction of the glass sheet 4 that is located on the other side.
<Eighteenth Embodiment>
[0178] Further, as illustrated in FIG. 27, laser beams L1 and L2 may be radiated on both
front and back sides of the laminate 1, and the position P1 of the focal point of
the laser beam L1 and a position Q1 of the focal point of the laser beam L2 may be
set at the middle positions in the thickness direction of the respective glass sheets
4 that are located on the incident side of the laser beams L1 and L2 (in the example
of FIG. 27, the upper glass sheet 4 in the case of the upper laser beam L1, and the
lower glass sheet 4 in the case of the lower laser beam L2).
<Nineteenth Embodiment>
[0179] A nineteenth embodiment of the present invention relates to a cutting method for
a laminate obtained by integrally laminating glass sheets on both surfaces of a resin
sheet. This cutting method comprises a protection step of covering the surfaces of
the laminate with protective tapes, a cutting step of carrying out laser fusing on
the laminate covered with the protective tapes, and a separation step of separating
the protective tapes from the surfaces of the laminate subjected to the laser fusing.
[0180] Specifically, as illustrated in FIG. 28, the cutting method for a laminate according
to the nineteenth embodiment is incorporated into a serial manufacturing process for
a laminate. That is, the manufacturing process for a laminate comprises a step S1
of preparing the laminate 1 obtained by integrally laminating the glass sheets 4 on
both surfaces of the resin sheet 2 through an intermediation of the adhesive layers
3, respectively, a step S2 of attaching separable protective tapes 20 to both surfaces
of the laminate 1, a step S3 of carrying out laser fusing on the laminate 1 having
the protective tapes 20 attached thereto so as to obtain a predetermined shape, a
step S4 of separating the protective tapes 20 from the laminate 1 subjected to the
laser fusing, and a step S5 of chamfering the end surface of the laminate 1 from which
the protective tapes 20 are separated.
[0181] With this method, the laser fusing is carried out under a state in which the exposed
surface of each glass sheet 4 is protected by the protective tape 20, and hence, even
when molten foreign matter is generated from the glass and the resin at the time of
fusing, the molten foreign matter does not directly adhere to the surface of the glass
sheet 4. Thus, when the protective tape 20 is separated from the surface of the glass
sheet 4 of the laminate 1 after the fusing, the cleanliness of the surface of the
glass sheet 4 can be maintained easily and reliably.
[0182] In this case, the protective tape 20 is not particularly limited as long as the protective
tape 20 is separable from the surface of the glass sheet 4. In a case of using an
ultraviolet separating tape and a heat separating tape, an ultraviolet irradiation
step and a heating step are required to decrease the pressure sensitive adhesive strength,
but there is a risk in that those steps cause damage to the glass sheet 4 at a point
starting from a microcrack generated in the end surface of the glass sheet 4 subjected
to the laser fusing. Therefore, as the protective tape 20, it is preferred to use
a low-pressure sensitive adhesive tape that does not require any treatment such as
heating at the time of separation.
<Twentieth Embodiment>
[0183] A twentieth embodiment of the present invention relates to a processing method that
comprises cutting of a laminate obtained by integrally laminating a glass sheet on
at least one surface of a resin sheet. This processing method is, for example, applied
to processing of the laminate 1 illustrated in FIG. 10.
[0184] First, referring to FIG. 29a, description is given of the structure of the laminate
1 to which the processing method according to the twentieth embodiment is applied.
The laminate 1 illustrated in FIG. 29a is obtained by integrally laminating the glass
sheets 4 on both surfaces of the resin sheet 2. One or both of the glass sheets 4
may be integrally laminated on the resin sheet 2 through an intermediation of an adhesive
layer, but in a case where the adhesive layer is omitted as in the example of FIG.
29a, the glass sheet 4 is integrally laminated on the resin sheet 2 by, for example,
welding.
[0185] The laminate 1 having the above-mentioned structure is cut out into a predetermined
shape and dimensions through a cutting step of executing a cutting process such as
laser fusing and water jet cutting, and has a cut surface 1b formed through the cutting
step. As illustrated in an enlarged view of FIG. 29a, a cut surface 4b of the upper
glass sheet 4 that forms the cut surface 1b of the laminate 1 is a rough surface having
small projections and depressions in a continuous manner, and has innumerable cracks
CR. Note that, although detailed illustration is omitted, a cut surface 4b of the
lower glass sheet 4 has similar surface property to that of the cut surface 4b of
the upper glass sheet 4. Further, although illustration is similarly omitted, a cut
surface 2b of the resin sheet 2 is a rough surface having small projections and depressions
in a continuous manner.
[0186] The processing method according to the twentieth embodiment has a feature in the
structure of a finishing step of finishing the cut surface 1b of the laminate 1 that
is formed into the rough surface as described above through the cutting step (with
a predetermined accuracy). To give a brief description, the processing method has
a feature in that the finishing step comprises a first phase of finishing the cut
surfaces 4b of the glass sheets 4, and a second phase of finishing the cut surface
2b of the resin sheet 2. Now, referring to FIGS. 29b and 29c, the first phase of finishing
the cut surfaces 4b of the glass sheets 4 is described in detail, and subsequently,
referring to FIGS. 30a and 30b, the second phase of finishing the cut surface 2b of
the resin sheet 2 is described in detail.
[0187] FIGS. 29b and 29c conceptually illustrate the first phase of the finishing step of
finishing the cut surface 1b of the laminate 1. In the first phase, the cut surfaces
4b of the glass sheets 4 are processed (finished) by grinding, and at least a part
of the cut surface 2b of the resin sheet 2 is left in an unprocessed state. Specifically,
a grinding tool 30 having a grinding surface 31 with a V-shape in cross section, which
is capable of simultaneously grinding both end portions of the cut surface 1b of the
laminate 1 in the thickness direction, that is, the cut surfaces 4b of the glass sheets
4, is caused to rotate and approach the laminate 1 that is held in a predetermined
posture, and the grinding surface 31 of the grinding tool 30 is pressed against the
cut surfaces 4b of the glass sheets 4 to grind the cut surfaces 4b (end portions of
the glass sheets 4 including the cut surfaces 4b). The grinding is continued until
the end portions of the glass sheets 4 are cut off to the extent that the small projections
and depressions, the cracks CR, and the like contained in the cut surfaces 4b are
removed substantially completely. The dimension of cutting off the end portion of
each glass sheet 4 differs depending on the cutting method employed for cutting the
laminate 1, the thickness of the glass sheet 4, and the like, and is set to, for example,
about 100 to 300 µm with respect to the cut surface 4b. In the twentieth embodiment,
a part of the cut surface 2b of the resin sheet 2 (both end portions of the cut surface
2b in the thickness direction) is also processed by the grinding [see FIG. 29c]. Thus,
when the grinding is completed, the cut surfaces 4b of the glass sheets 4 are processed
into smooth surfaces 4c having a tapered shape as illustrated in FIG. 29c, and a center
region of the cut surface 2b of the resin sheet 2 in the thickness direction is left
in the unprocessed state.
[0188] It is preferred that the grinding in the above-mentioned first phase be executed
as so-called constant-pressure grinding, which is gradually progressed under a state
in which the grinding tool 30 is brought into contact with the surfaces to be processed
(cut surfaces 4b of the glass sheets 4 and both end portions of the cut surface 2b
of the resin sheet 2 in the thickness direction) at a constant contact force. This
is for the purpose of preventing, to the extent possible, trouble such as breaking
that may occur in the glass sheets 4 due to application of an excessive pressure to
the glass sheets 4 during the grinding. Conversely, when the breaking or the like
of the glass sheets 4 along with the grinding can be prevented to the extent possible
by employing the constant-pressure grinding, the feed speed of the grinding tool 30
can be increased so as to enhance the finishing efficiency of the cut surfaces 4b
of the glass sheets 4.
[0189] Further, as illustrated in FIG. 29c, the grinding is progressed under a state in
which a clearance C is provided between the cut surface 2b of the resin sheet 2 and
a bottom portion of the grinding surface 31 of the grinding tool 30. This is for the
purpose of enabling smooth discharging of chips, which are generated along with the
grinding, to the outside of the processing point, to thereby prevent decrease in grinding
accuracy and the breaking of the glass sheets 4 to the extent possible.
[0190] When the cut surface 1b of the laminate 1 is finished in the above-mentioned manner
by the above-mentioned grinding, the laminate 1 is transported to the second phase
of the finishing step. In the second phase, only the cut surface 2b that is left in
the unprocessed state is processed by cutting work. More specifically, as illustrated
in FIGS. 30a and 30b, the end portion of the resin sheet 2 including the cut surface
2b that is left in the unprocessed state is cut off along a preset finishing line
FL (a region indicated by cross hatching in FIG. 30a is cut off), and thus the cut
surface 2b of the resin sheet 2 is finished into a smooth surface 2c extending in
the thickness direction. The cutting work is executed through use of a cutting tool
such as an end mill, and as the cutting tool, a non-coated cutting tool having no
protective coating formed on a surface thereof is suitably used. This is because the
non-coated cutting tool has blade portions (cutting edges) exposed in a sharp state
without being covered with the protective coating, and hence the sharpness for cutting
a resin is more satisfactory as compared to a coated cutting tool having a protective
coating formed on a surface thereof, with the result that the non-coated cutting tool
may process the cut surface 2b of the resin sheet 2 particularly efficiently. Note
that, the preset finishing line FL in the state illustrated in FIG. 30a may be shifted
toward the cut surface 2b of the resin sheet 2 so that the smooth surface 2c of the
resin sheet 2 protrudes with respect to the smooth surfaces 4c of the glass sheets
4 after the cutting (see FIG. 10).
[0191] When the cut surface 2b of the resin sheet 2 is finished into the smooth surface
2c in the manner described above, the finishing step of finishing the cut surface
1b of the laminate 1 is completed.
[0192] As described above, in the twentieth embodiment, when finishing the cut surface 1b
of the laminate 1, the first phase is first executed to process the cut surfaces 4b
of the glass sheets 4 by grinding, and to leave a part of the cut surface 2b of the
resin sheet 2 in the unprocessed state. With this method, when grinding the cut surfaces
4b of the glass sheets 4 (end portions including the cut surfaces 4b), large resin
chips are not easily generated, and in addition, the resin sheet 2 functions as a
backup member for the glass sheets 4 so that the glass sheets 4 are not easily distorted
when the grinding tool 30 is pressed against the cut surfaces 4b of the glass sheets
4. In particular, this effect is remarkably produced in the case where the resin sheet
2 is relatively thicker than each glass sheet 4 as in this embodiment. Thus, when
grinding the cut surfaces 4b of the glass sheets 4, trouble such as breaking and chipping
of the glass sheets 4 can be prevented to the extent possible while increasing the
feed speed of the grinding tool 30 so as to enhance the finishing efficiency of the
glass sheets 4.
[0193] Further, in the second phase subsequent to the first phase of the finishing step,
only the cut surface 2b of the resin sheet 2 that is left in the unprocessed state
is processed. Thus, a processing method suited to finish the resin can be selected
for use, and hence the cut surface 2b of the resin sheet 2 can be finished efficiently
with a predetermined accuracy. Specifically, the cutting work is carried out to finish
the cut surface 2b of the resin sheet 2 with a predetermined accuracy. The cutting
work is executed through use of a working tool such as an end mill, in which the distance
between adjacent blade portions is large so that the working tool is not easily clogged.
Due to this aspect, the feed speed of the working tool may be increased so as to finish
the cut surface 2b of the resin sheet 2 efficiently.
[0194] As described above, in the twentieth embodiment, the finishing of the cut surface
1b of the laminate 1, which may be completed even in a single phase, is executed in
two separate phases intendedly. Therefore, it seems that the man-hours and cost required
to finish the cut surface 1b of the laminate 1 are increased, but the amount of processing
efficiency enhanced by employing the twentieth embodiment is larger than the amount
of processing efficiency decreased due to the problem that may arise in the case where
the cut surface 1b of the laminate 1 is to be finished in a single phase. Thus, according
to this embodiment, the cut surface 1b of the laminate 1 obtained by integrally laminating
the glass sheets 4 on the resin sheet 2 can be finished efficiently.
[0195] Note that, in the grinding to be executed in the first phase, from the viewpoint
of preventing the clogging of the grinding surface 31 of the grinding tool 30 and
therefore preventing the breaking of the glass sheets 4 due to the clogging to the
extent possible, it is desired to process only the cut surfaces 4b of the glass sheets
4. However, a dimensional tolerance or the like is generally set for the thickness
of the laminate 1, and hence, when only the cut surfaces 4b of the glass sheets 4
are to be ground without grinding any part of the cut surface 2b of the resin sheet
2, it is necessary to manage and control grinding conditions (feed amount, posture,
and the like of the grinding tool 30) with extreme precision, thus leading to a risk
of increase in processing cost on the contrary. In this respect, according to this
embodiment, in the first phase in which the grinding is executed, at least a part
of the cut surface 2b of the resin sheet 2 is left in the unprocessed state. Conversely,
a part of the cut surface 2b of the resin sheet 2 is allowed to be ground in the first
phase. Therefore, the grinding conditions in the first phase can be relaxed, and the
grinding can be executed rapidly.
[0196] The processing method for the laminate 1 according to the twentieth embodiment is
described above, and various modifications may be made thereto.
[0197] For example, as the grinding tool 30 to be used for finishing the cut surfaces 4b
of the glass sheets 4 in the first phase of the finishing step, there may be used,
for example, a grinding tool 30 having a tapered grinding surface 32 as illustrated
in FIG. 31a, and a grinding tool 30 having a disc-like grinding surface 33 as illustrated
in FIG. 31b. In the case of using the grinding tool 30 as illustrated in FIG. 31 a
or 31b, it is necessary to individually execute a process of finishing the cut surface
4b of the upper glass sheet 4 and a process of finishing the cut surface 4b of the
lower glass sheet 4. However, the chips generated along with the grinding can be discharged
more efficiently as compared to the above-mentioned embodiment, and hence the feed
speed of the grinding tool 30 can be increased by an amount corresponding to the increase
in efficiency, with the result that each glass sheet 4 can be finished efficiently.
Also in the case of using the grinding tool 30 as illustrated in FIG. 31a or 31b,
it is desired that the grinding for finishing the cut surfaces 4b of the glass sheets
4 be executed as the so-called constant-pressure grinding, which is carried out under
a state in which the grinding tool 30 is brought into contact with each glass sheet
4 at a constant contact force.
[0198] Further, in the first phase of the finishing step, the grinding may be executed a
plurality of times through use of grinding tools 30 having different surface roughnesses
(grit sizes) of the grinding surfaces. Although illustration is omitted, a case of
using three types of grinding tools having different surface roughnesses of the grinding
surfaces is taken as an example. First, the end portion of each glass sheet 4 is roughly
ground through use of a grinding tool 30 having the largest surface roughness of the
grinding surface (grinding tool 30 having a grinding surface with a grit size of,
for example, #120). Subsequently, the end portion of the glass sheet 4 is roughly
finished through use of a grinding tool 30 having the second largest surface roughness
of the grinding surface (grinding tool 30 having a grinding surface with a grit size
of, for example, #400). Finally, the end portion of the glass sheet 4 is precisely
finished through use of a grinding tool 30 having the smallest surface roughness of
the grinding surface (grinding tool 30 having a grinding surface with a grit size
of, for example, #1000). With this method, the cut surface 4b of the glass sheet 4
is easily finished in a more rapid manner as compared to the case of finishing the
cut surface 4b of the glass sheet 4 with a single grinding tool 30 as described with
reference to FIGS. 29b and 29c.
[0199] Further, the processing method that may be employed for the second phase of the finishing
step is not limited to the cutting work, and the grinding may be employed similarly
to the first phase. This is because the cut surfaces 4b of the glass sheets 4 are
not processed in the second phase, and hence, even when large resin chips are generated
due to the clogging of the grinding tool that occurs along with the grinding of the
cut surface 2b of the resin sheet 2 in the second phase, the breaking of the glass
sheets 4 due to the resin chips can be prevented to the extent possible.
[0200] Further, the manner of finishing the cut surface 1b of the laminate 1, that is, the
manner of finishing the cut surfaces 4b of the glass sheets 4 and the cut surface
2b of the resin sheet 2 is not even limited to that of the above-mentioned embodiment,
and may be changed arbitrarily. For example, in the first phase of the finishing step,
as illustrated in FIG. 32a, the end portions including the cut surfaces 4b of the
glass sheets 4 are ground into a rectangular shape in cross section (portions of the
glass sheets 4 indicated by cross hatching in FIG. 32a are ground), and thus the cut
surfaces 4b are finished into the smooth surfaces 4c that are parallel to the thickness
direction of the laminate 1 [see FIG. 32b]. After that, in the second phase, the end
portion including the cut surface 2b of the resin sheet 2 is cut off by cutting work
along the preset finishing line FL illustrated in FIG. 32b (a portion of the resin
sheet 2 indicated by cross hatching in FIG. 32b is cut off by cutting work). In this
manner, as illustrated in FIG. 32c, the cut surfaces 4b of the glass sheets 4 may
be finished into the smooth surfaces 4c that are parallel to the thickness direction
of the laminate 1, and the cut surface 2b of the resin sheet 2 may also be finished
into the smooth surface 2c that is parallel to the thickness direction of the laminate
1.
[0201] The above description is directed to the case where the processing method according
to the twentieth embodiment is applied when finishing the cut surface 1b of the laminate
1 obtained by integrally laminating the glass sheets 4 on both surfaces of the resin
sheet 2, but the processing method according to the twentieth embodiment may also
be applied suitably when finishing the cut surface 1b of a laminate 1 obtained by
integrally laminating the glass sheet on only one of both surfaces of the resin sheet
2. As an example thereof, FIGS. 33a to 33c schematically illustrate a state of finishing
the cut surface 1b of the laminate 1 obtained by integrally laminating the glass sheet
4 on only a front surface (upper surface) of the resin sheet 2.
[0202] First, in the first phase illustrated in FIG. 33a, the end portion including the
cut surface 4b of the glass sheet 4 is ground, that is, a portion indicated by cross
hatching in FIG. 33a is ground, and thus the cut surface 4b of the glass sheet 4 is
finished into the smooth surface 4c having a tapered shape as illustrated in FIG.
33b. Subsequently, in the second phase illustrated in FIG. 33b, the end portion including
the cut surface 2b of the resin sheet 2 is cut off by cutting work, that is, a portion
indicated by cross hatching in FIG. 33b is cut off by cutting work (the end portion
of the resin sheet 2 is cut off by cutting work along the preset finishing line FL),
and thus the cut surface 2b of the resin sheet 2 is finished into the smooth surface
2c that is formed continuously of a flat surface extending along the thickness direction
of the laminate 1 and a tapered surface inclined with respect to the thickness direction
of the laminate 1.
<Twenty-first Embodiment>
[0203] A twenty-first embodiment of the present invention relates to a cutting method for
a brittle sheet-like object as typified by a glass sheet and a laminate obtained by
integrally laminating a glass sheet on a resin sheet. This cutting method is, for
example, applied to the cutting step of the above-mentioned twentieth embodiment.
[0204] Now, the twenty-first embodiment is described with reference to the drawings.
[0205] FIG. 34a is a schematic plan view illustrating a cutting apparatus 40 according to
the twenty-first embodiment, and FIG. 34b is a schematic partial sectional view illustrating
the cutting apparatus 40 (schematic sectional view taken on the arrows X-X in FIG.
34a). This cutting apparatus 40 is used for cutting a brittle sheet-like object A
such as a glass sheet alone or a laminate obtained by integrally laminating a glass
sheet on at least one of both surfaces of a resin sheet. More specifically, as illustrated
in FIGS. 34a and 34b, the cutting apparatus 40 is used for carrying out so-called
laser fusing, which involves radiating the laser beam LB from the top along a preset
cutting line CL of the brittle sheet-like object A placed in a horizontal posture,
and sequentially melting and removing the preset cutting line CL due to irradiation
heat of the laser beam LB, to thereby separate and divide the brittle sheet-like object
A into a product portion and a non-product portion across the preset cutting line
CL. In this case, as illustrated also in FIG. 34c, there is described an example of
the cutting apparatus 40 to be used for cutting out a product portion M having an
oblong shape from the laminate 1 that is the brittle sheet-like object A having a
substantially rectangular shape in plan view as an overall shape, to thereby divide
the laminate 1 into the product portion M having an oblong shape and a non-product
portion N having a hollow rectangular shape. Note that, the product portion M having
an oblong shape is used, for example, for a cover member (protective cover) of a touch
panel to be built into a portable electronic device.
[0206] First, the structure of the laminate 1 that is the brittle sheet-like object A to
be cut is described. As illustrated in FIG. 34b, the laminate 1 is obtained by integrally
laminating the glass sheets 4 on both surfaces of the resin sheet 2 through an intermediation
of the adhesive layers 3, respectively. The adhesive layers 3 may be omitted, and
in the case where the adhesive layers 3 are omitted, the glass sheets 4 may be integrally
laminated on the resin sheet 2 by, for example, welding.
[0207] Next, the structure of the cutting apparatus 40 is described in detail. As illustrated
in FIG. 34b, the cutting apparatus 40 mainly comprises a laser irradiation apparatus
41 and a gas jet nozzle 42 arranged above the laminate 1, and a support member 43
arranged below the laminate 1. The laser irradiation apparatus 41 and the gas jet
nozzle 42 are movable relative to the support member 43 in a direction along a horizontal
plane.
[0208] The laser irradiation apparatus 41 mainly comprises a laser oscillator serving as
a source of the laser beam LB as typified by, for example, a carbon dioxide laser
and a YAG laser, and optical components such as a condenser lens. The laser irradiation
apparatus 41 is configured to radiate the laser beam LB in a substantially perpendicular
direction toward the preset cutting line CL of the laminate 1. The laser beam LB may
be continuous light and pulsed light.
[0209] The gas jet nozzle 42 is configured to jet the assist gas AG toward a portion irradiated
with the laser beam LB in the laminate 1 so as to blow off molten foreign matter that
is generated at the cut (fused) portion of the laminate 1 along with the irradiation
of the preset cutting line CL of the laminate 1 with the laser beam LB. In this embodiment,
the gas jet nozzle 42 is arranged at a position above the product portion M side of
the laminate 1, and the assist gas AG is obliquely jetted from the position above
the product portion M side toward the portion irradiated with the laser beam LB. Thus,
the molten foreign matter generated at the fused portion of the laminate 1 is blown
off toward the non-product portion N by the assist gas AG. Therefore, it is possible
to prevent, to the extent possible, such a situation that the molten foreign matter
adheres to the cut end surface or the like of the product portion M to cause a defective
shape of the product portion M.
[0210] Note that, the manner of arranging the gas jet nozzle 42, that is, the manner of
jetting the assist gas AG is not limited to that of the above-mentioned embodiment.
For example, the gas jet nozzle 42 may be arranged directly above the preset cutting
line CL, and the assist gas AG may be jetted in a substantially perpendicular direction
to the portion irradiated with the laser beam LB. Further, the gas jet nozzle 42 may
be provided as necessary, and is not provided necessarily.
[0211] The support member 43 is a member for supporting the laminate 1 to be cut in a horizontal
posture from the bottom side, and comprises a first support section 45 capable of
supporting the product portion M having an oblong shape (or a region to be formed
into the product portion M), and a second support section 46 capable of supporting
the non-product portion N having a hollow rectangular shape (or a region to be formed
into the non-product portion N). Both the support sections 45 and 46 are partitioned
by the preset cutting line CL of the laminate 1, in other words, a groove portion
44 provided along an irradiation path of the laser beam LB. The groove portion 44
is a portion provided so as to prevent increase in residual strain of the cut end
surface and generation of small defects in the cut end surface to the extent possible.
The increase in residual strain and the generation of small defects may occur when
the laser beam LB passing through the laminate 1 reflects in proximity to the lower
surface of the laminate 1 and re-enters the lower surface of the laminate 1 so as
to apply unnecessary irradiation heat to the cut end surface of the laminate 1 (in
particular, the product portion M).
[0212] As illustrated in FIG. 34b, the first support section 45 is formed so that a support
surface 45a thereof is located slightly higher than a support surface 46a of the second
support section 46. Thus, a slight height difference δ2 is provided between both the
support surfaces 45a and 46a. In this case, a spacer 47 having a thickness corresponding
to a value of the height difference δ2 to be provided is integrally laminated on an
upper surface of a base portion 45' formed at a thickness that is substantially equal
to the thickness of the second support section 46, to thereby provide the height difference
δ2 between the support surfaces 45a and 46a of both the support sections 45 and 46.
That is, in this embodiment, the first support section 45 is formed of the base portion
45' and the spacer 47 integrally laminated on the upper surface thereof. The height
difference δ2 between both the support surfaces 45a and 46a is set to 0.01 mm or more
and 0.2 mm or less (0.01 mm≤δ2≤0.2 mm), and the reason for setting such a numerical
range of the height difference δ2 is described later in detail. The spacer 47 that
may be used is not particularly limited, and for example, a tape material and a shim
plate made of a resin, a rubber, or a metal may be used. The spacer 47 may be formed
of a single shim plate or the like, or may be formed by laminating a plurality of
shim plates or the like.
[0213] Note that, means for obtaining the support member 43 having the predetermined height
difference δ2 provided between the support surfaces 45a and 46a of both the support
sections 45 and 46 is not limited to that described above. That is, as illustrated
in FIG. 35a, the support member 43 may be obtained in such a manner that plate members
49 and 50 having a thickness difference corresponding to the height difference δ2
to be provided are adhered to an upper surface of a base member 48 for holding the
support member 43. Alternatively, as illustrated in FIG. 35b, the support member 43
may be formed by preparing a plate member 51 having the groove portion 44 provided
along the irradiation path of the laser beam LB (preset cutting line CL), and shaving
off a predetermined region of the plate member 51 (region to be formed into the second
support section 46, which is indicated by cross hatching in FIG. 35b) by turning.
Note that, in the structure illustrated in FIG. 35b, the amount of man-hours required
to manufacture the support member 43 is larger as compared to the structures illustrated
in FIGS. 34b and 35a, and hence the support member 43 illustrated in FIG. 34b or 35a
is preferred.
[0214] Although illustration is omitted, the cutting apparatus 40 may further comprise suction
means for sucking the laminate 1 onto the support member 43. When the cutting process
(melting and removing) for the preset cutting line CL is sequentially executed under
a state in which the suction means described above is provided so as to suck the laminate
1 onto the support member 43, the movement of the laminate 1 relative to the support
member 43 can be prevented to the extent possible. Thus, the cutting accuracy is enhanced,
and hence a high-quality product portion M can be obtained.
[0215] The cutting apparatus 40 according to the twenty-first embodiment has the above-mentioned
structure, and is configured to divide the laminate 1, which is supported in a horizontal
posture from the bottom side by the support member 43, into the product portion M
and the non-product portion N across the preset cutting line CL in the following manner.
First, the laser irradiation apparatus 41 radiates the laser beam LB toward the laminate
1 (or the preset cutting line CL of the laminate 1) while moving the laser irradiation
apparatus 41 and the gas jet nozzle 42 relative to the support member 43, to thereby
melt and remove, in a sequential manner, the preset cutting line CL of the laminate
1 due to the irradiation heat of the laser beam LB. At this time, the gas jet nozzle
42 jets the assist gas AG toward the portion irradiated with the laser beam LB in
the laminate 1 so as to blow off, toward the non-product portion N, the molten foreign
matter that is formed along with the irradiation with the laser beam LB.
[0216] The laser irradiation apparatus 41 and the gas jet nozzle 42 may be moved relative
to the support member 43 every time the laser beam LB radiated toward the preset cutting
line CL (or a partial region of the preset cutting line CL) passes through the lower
surface of the laminate 1. Alternatively, the laser irradiation apparatus 41 and the
gas jet nozzle 42 may be moved relative to the support member 43 every time the partial
region of the preset cutting line CL of the laminate 1 is molten and removed by a
predetermined thickness. That is, the cutting of the preset cutting line CL may be
completed when the laser beam LB is scanned in one loop along the preset cutting line
CL of the laminate 1, or may be completed when the laser beam LB is scanned in a plurality
of loops along the preset cutting line CL of the laminate 1. When the cutting of the
preset cutting line CL is completed by melting and removing all the preset cutting
line CL, as illustrated in FIG. 34c, the laminate 1 is then divided across the preset
cutting line CL into the product portion M having an oblong shape and the non-product
portion N having a hollow rectangular shape.
[0217] Further, as the cutting apparatus 40 to be used for dividing the laminate 1 into
the product portion M and the non-product portion N in the manner described above,
the cutting apparatus 40 used in this embodiment comprises the support member 43 in
which the support surface 45a of the first support section 45 for supporting the product
portion M is located higher than the support surface 46a of the second support section
46. Thus, the cutting (in this case, melting and removing) of the preset cutting line
CL can be progressed and completed under a state in which the product portion M (or
the region to be formed into the product portion M) is located constantly higher than
the non-product portion N (or the region to be formed into the non-product portion
N). Therefore, it is possible to reduce, to the extent possible, the risk in that
a small defect such as a microcrack is formed in the cut end surface of the glass
sheet 4 (in particular, the lower glass sheet 4) that forms the product portion M
in the phase immediately before the completion of the cutting of the preset cutting
line CL due to the fact that the product portion M is located lower than the non-product
portion N. The reason is as follows. That is, with this structure, even when the non-product
portion N drops off, for example, in the phase immediately before the completion of
the cutting (laser fusing) of the laminate 1 and hence the lower glass sheet 4 that
forms the laminate 1 is forcibly snapped, the small defect such as a microcrack is
formed not in the cut end surface of the product portion M but in the cut end surface
of the non-product portion N.
[0218] In particular, in a case where the laminate 1 comprising the glass sheet 4 that is
thinned to a thickness of about 0.01 mm or more and 0.3 mm or less (in this embodiment,
the glass sheet 4 having a thickness of 0.1 mm) is divided into the product portion
M and the non-product portion N across the preset cutting line CL, the glass sheet
4 (in particular, the lower glass sheet 4) that forms the laminate 1 is liable to
be snapped forcibly in the phase immediately before the completion of the cutting
of the preset cutting line CL, and hence the cutting apparatus 40 according to this
embodiment is significantly advantageous.
[0219] Note that, when the cutting (melting and removing) of the preset cutting line CL
is completed under the state in which the product portion M is located higher than
the non-product portion N, as described above, it is possible to reduce, to the extent
possible, the risk in that the small defect is formed in the cut end surface of the
product portion M. However, when the height difference δ2 between both the support
surfaces 45a and 46a is extremely small, it is hard to deny a risk in that a part
or all of the support surface 45a of the first support section 45 is located lower
than the support surface 46a of the second support section 46 due to effects of a
processing error at the time of manufacturing the support member 43 and/or thermal
deformation of at least one of both the support sections 45 and 46 along with the
irradiation with the laser beam LB. As a measure against the risk, the support surface
45a of the first support section 45 is located higher by 0.01 mm or more than the
support surface 46a of the second support section 46. Thus, the height difference
δ2 between both the support surfaces 45a and 46a can absorb the amount of the processing
error at the time of manufacturing the support member 43 and the amount of the thermal
deformation of the support sections 45 and 46 along with the irradiation with the
laser beam LB. In a case where the support surface 45a of the first support section
45 is located higher by more than 0.2 mm than the support surface 46a of the second
support section 46, on the other hand, the amount of hanging down the non-product
portion N due to a self-weight thereof becomes larger, and due to a bending stress
generated therefrom, the small defect is liable to be formed in the cut end surface
of the glass sheet 4 that forms the product portion M, thus increasing the risk of
the breaking of the glass sheet 4 that forms the product portion M.
[0220] As described above, when the support surface 45a of the first support section 45
is located higher than the support surface 46a of the second support section 46 within
the range of 0.01 mm or more and 0.2 mm or less (the height difference δ2 between
both the support surfaces 45a and 46a is set to 0.01 mm or more and 0.2 mm or less)
as in this embodiment, a high-quality product portion M can be obtained stably.
[0221] The cutting apparatus 40 and the cutting method for the brittle sheet-like object
A according to the twenty-first embodiment are described above, and various modifications
may be made to the cutting apparatus 40 (cutting method).
[0222] For example, in the above-mentioned cutting apparatus 40, both of the first support
section 45 and the second support section 46 that form the support member 43 are provided
in a stationary manner, but the cutting apparatus 40 may further comprise an elevating
mechanism for raising and lowering at least one of both the support sections 45 and
46. With this structure, during the execution of the cutting process for the preset
cutting line CL, the heights of the support surfaces 45a and 46a of both the support
sections 45 and 46 can be adjusted arbitrarily, and hence the cutting of the preset
cutting line CL is easily progressed and completed under a state in which the laminate
1 is held in an optimum posture.
[0223] Specifically, for example, as illustrated in FIG. 36a, during a period after the
start of the cutting of the preset cutting line CL until immediately before the completion
of the cutting of the preset cutting line CL, the product portion M and the non-product
portion N are located at the same height. After that, as illustrated in FIG. 36b,
when the cutting process is progressed to the state immediately before the completion
of the cutting of the preset cutting line CL, the first support section 45 and the
second support section 46 are raised and lowered relatively (in the example of FIG.
36b, the second support section 46 is lowered). Through this operation, the product
portion M is located higher than the non-product portion N, and the cutting of the
preset cutting line CL is completed in this state.
[0224] With this structure, the cutting process for the preset cutting line CL can be progressed
under a state in which the product portion M and the non-product portion N are located
within the same plane, thus producing an advantage in that the probability of formation
of the small defect caused by the product portion M or the non-product portion N that
is hung down due to the self-weight thereof can also be reduced to the extent possible.
[0225] As a matter of course, the first support section 45 and the second support section
46 may be raised and lowered relatively not at the time immediately before the completion
of the cutting of the preset cutting line CL but at the time, for example, when the
cutting of the preset cutting line CL is progressed approximately halfway through
the entire process. Also through this operation, the support surface 45a of the first
support section 45 may be located higher than the support surface 46a of the second
support section 46 (the product portion M may be located higher than the non-product
portion N), and the cutting of the preset cutting line CL may be completed in this
state. That is, it is only necessary that the support surface 45a of the first support
section 45 be located higher than the support surface 46a of the second support section
46 in the phase immediately before the completion of the cutting of the preset cutting
line CL, and the cutting of the preset cutting line CL be completed in this state.
[0226] The above description is directed to the case where the laminate 1 that is the brittle
sheet-like object A is divided into one product portion M and one non-product portion
N. However, the present invention may also be applied suitably to a case where, as
illustrated in FIG. 37, a plurality of (four) product portions M are cut out from
a laminate 1 having a plurality of (in the example of FIG. 37, four) preset cutting
lines CL, to thereby divide the laminate 1 into the four product portions M and one
non-product portion N. The present invention may also be applied suitably to a case
where, as illustrated in FIG. 38, a laminate 1 having a linear preset cutting line
CL is irradiated with the laser beam LB to cut the preset cutting line CL, to thereby
divide the laminate 1 into a product portion M and a non-product portion N across
the preset cutting line CL.
[0227] Further, the above description is directed to the case where, as the brittle sheet-like
object A, the laminate 1 obtained by integrally laminating the glass sheets 4 on both
surfaces of the resin sheet 2 is divided into the product portion M and the non-product
portion N across the preset cutting line CL, but the present invention may also be
applied suitably to a case where, as the brittle sheet-like object A, a glass sheet
alone or a laminate obtained by integrally laminating the glass sheet 4 on only one
of both surfaces of the resin sheet 2 is divided into the product portion M and the
non-product portion N.
[0228] Further, the cutting apparatus 40 and the cutting method according to the twenty-first
embodiment may be used not only to the case of executing the laser fusing described
above, but also suitably to a case of executing so-called laser cleaving (not shown).
Reference Signs List
[0229]
- 1
- laminate
- 1a
- corner portion
- 2
- resin sheet
- 2a
- end surface
- 3
- adhesive layer
- 4
- glass sheet
- 4a
- end surface
- 5
- depressed portion
- 5a
- bending portion
- 6
- projecting portion
- 6a
- bending portion
- 7
- opening portion
- 7a
- bending portion
- 20
- protective tape
[0230] Preferred embodiments of the application:
- 1. A laminate, comprising:
a resin sheet; and
a glass sheet having a thickness of 300 µm or less,
the glass sheet being integrally laminated on at least one of both surfaces of the
resin sheet,
wherein an end surface of the glass sheet is chamfered.
- 2. The laminate according to claim 1, wherein at least a part of an end surface of
the resin sheet protrudes with respect to the end surface of the glass sheet.
- 3. The laminate according to claim 1 or 2, wherein the glass sheet is integrally laminated
on each of both the surfaces of the resin sheet.
- 4. The laminate according to any one of claims 1 to 3, wherein a corner portion formed
by crossing adjacent two edges has a curved shape or a polygonal shape obtained by
combining obtuse angles.
- 5. The laminate according to any one of claims 1 to 4, further comprising a deformed
portion formed of a projecting portion or a depressed portion on an outer periphery
of the laminate,
wherein the deformed portion comprises a bending portion, and the bending portion
has a curved shape.
- 6. The laminate according to any one of claims 1 to 5, further comprising an opening
portion formed in a flat surface of the laminate,
wherein the opening portion comprises a bending portion on a periphery thereof, and
the bending portion has a curved shape.
- 7. A manufacturing method for a laminate, comprising:
a lamination step of integrally laminating a glass sheet having a thickness of 300
µm or less on at least one of both surfaces of a resin sheet; and
a chamfering step of chamfering an end surface of the glass sheet that is integrally
laminated on the resin sheet in the lamination step.
- 8. The manufacturing method for a laminate according to claim 7, wherein the chamfering
step comprises chamfering the resin sheet as well.
- 9. The manufacturing method for a laminate according to claim 7 or 8, wherein the
lamination step comprises integrally laminating the glass sheet on each of both the
surfaces of the resin sheet.
- 10. A laminate, comprising:
a resin sheet; and
glass sheets having a thickness of 300 µm or less,
the glass sheets being integrally laminated on both surfaces of the resin sheet,
wherein at least a part of an end surface of the resin sheet protrudes with respect
to end surfaces of the glass sheets.
- 11. The laminate according to claim 10, wherein each of the end surfaces of the glass
sheets comprises a tapered surface inclined away from the end surface of the resin
sheet toward an outer surface side of each of the glass sheets.
- 12. The laminate according to claim 10 or 11, wherein the resin sheet and the glass
sheets are adhered to each other with adhesive layers.
- 13. The laminate according to claim 12, wherein end surfaces of the adhesive layers
protrude with respect to the end surfaces of the glass sheets.
- 14. The laminate according to any one of claims 10 to 13, wherein the end surfaces
of the glass sheets and the end surface of the resin sheet are formed continuous with
each other into a projecting curved surface.
- 15. A cutting method for a laminate, comprising carrying out laser fusing by irradiating
the laminate with a laser beam from one side thereof, the laminate being obtained
by integrally laminating glass sheets on both surfaces of a resin sheet,
the laser beam having a focal point adjusted inside the laminate at a position that
is set within a range of more than 50% and 90% or less of an overall thickness of
the laminate from an incident surface side of the laser beam.
- 16. The cutting method for a laminate according to claim 15, wherein the position
of the focal point is set within a range of 60% or more and 80% or less of the overall
thickness of the laminate from the incident surface side of the laser beam.
- 17. The cutting method for a laminate according to claim 15 or 16, wherein a value
obtained by dividing power of the laser beam by scanning speed of the laser beam is
set to 0.001 to 1 W·min/mm.
- 18. The cutting method for a laminate according to any one of claims 15 to 17,
wherein the resin sheet has a thickness of 20 mm or less,
wherein the glass sheets have a thickness of 300 µm or less, and
wherein the resin sheet is thicker than the glass sheets.
- 19. A processing method for a laminate, comprising:
a cutting step of cutting the laminate obtained by integrally laminating a glass sheet
on at least one of both surfaces of a resin sheet; and
a finishing step of finishing a cut surface of the laminate that is formed in the
cutting step,
the finishing step comprising:
a first phase of processing a cut surface of the glass sheet by grinding, and leaving
at least a part of a cut surface of the resin sheet in an unprocessed state; and
a second phase of processing only the cut surface of the resin sheet that is left
in the unprocessed state.
- 20. The processing method for a laminate according to claim 19, wherein the grinding
in the first phase is executed under a state in which a grinding tool is brought into
contact with a surface to be processed at a constant contact force.
- 21. The processing method for a laminate according to claim 19 or 20, wherein the
grinding in the first phase is executed a plurality of times through use of grinding
tools having different surface roughnesses of grinding surfaces thereof.
- 22. The processing method for a laminate according to any one of claims 19 to 21,
wherein the second phase comprises processing, by cutting work, only the cut surface
of the resin sheet that is left in the unprocessed state.
- 23. The processing method for a laminate according to any one of claims 19 to 22,
wherein the glass sheet alone has a thickness of 0.01 mm or more and 0.7 mm or less.
- 24. The processing method for a laminate according to any one of claims 19 to 23,
wherein the thickness of the glass sheet alone is smaller than a thickness of the
resin sheet.
- 25. A cutting apparatus for a brittle sheet-like object, which is configured to cut
a preset cutting line of the brittle sheet-like object, which is supported in a horizontal
posture from a bottom side thereof by a support member, by radiating a laser beam
along the preset cutting line so as to divide the brittle sheet-like object into a
product portion and a non-product portion across the preset cutting line,
the support member comprising:
a first support section capable of supporting the product portion; and
a second support section capable of supporting the non-product portion,
wherein a support surface of the first support section is located higher than a support
surface of the second support section.
- 26. The cutting apparatus for a brittle sheet-like object according to claim 25, wherein
the support surface of the first support section is located higher than the support
surface of the second support section within a range of 0.01 mm or more and 0.2 mm
or less.
- 27. The cutting apparatus for a brittle sheet-like object according to claim 25 or
26, further comprising an elevating mechanism for raising and lowering at least one
of the first support section and the second support section.
- 28. The cutting apparatus for a brittle sheet-like object according to any one of
claims 25 to 27, wherein the brittle sheet-like object comprises a laminate obtained
by integrally laminating a glass sheet on at least one of both surfaces of a resin
sheet.
- 29. The cutting apparatus for a brittle sheet-like object according to claim 28,
wherein the glass sheet alone has a thickness of 0.01 mm or more and 1.0 mm or less,
and
wherein the resin sheet has a thickness of 0.01 mm or more and 10 mm or less.
- 30. The cutting apparatus for a brittle sheet-like object according to any one of
claims 25 to 27, wherein the brittle sheet-like object comprises a glass sheet.
- 31. The cutting apparatus for a brittle sheet-like object according to claim 30, wherein
the glass sheet has a thickness of 0.01 mm or more and 1.0 mm or less.
- 32. A cutting method for a brittle sheet-like object, comprising cutting a preset
cutting line of the brittle sheet-like object, which is supported in a horizontal
posture from a bottom side thereof by a support member, by radiating a laser beam
along the preset cutting line so as to divide the brittle sheet-like object into a
product portion and a non-product portion across the preset cutting line,
the cutting of the preset cutting line being completed under a state in which the
product portion is located higher than the non-product portion, the state being achieved
at least immediately before completion of the cutting of the preset cutting line.
- 33. The cutting method for a brittle sheet-like object according to claim 32, wherein
the product portion and the non-product portion are located at the same height during
a period until immediately before the completion of the cutting of the preset cutting
line.
- 34. The cutting method for a brittle sheet-like object according to claim 32 or 33,
wherein the cutting of the preset cutting line comprises melting and removing the
preset cutting line due to irradiation heat of the laser beam.